diff --git a/NEWS b/NEWS
index 1abf2a8f64..6d479faa75 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,12 @@
+=============================================
+NetworkManager-1.46
+Overview of changes since NetworkManager-1.46
+=============================================
+
+* Change internal ABI of NMSetting types and NMSimpleConnection. The layout of
+  these structs was already hidden from public headers since 1.34 and this change
+  should not be noticeable.
+
 =============================================
 NetworkManager-1.44
 Overview of changes since NetworkManager-1.42
diff --git a/src/libnm-core-impl/nm-setting-6lowpan.c b/src/libnm-core-impl/nm-setting-6lowpan.c
index e0b5d65071..42f4051a69 100644
--- a/src/libnm-core-impl/nm-setting-6lowpan.c
+++ b/src/libnm-core-impl/nm-setting-6lowpan.c
@@ -33,7 +33,8 @@ typedef struct {
  * Since: 1.14
  */
 struct _NMSetting6Lowpan {
-    NMSetting parent;
+    NMSetting               parent;
+    NMSetting6LowpanPrivate _priv;
 };
 
 struct _NMSetting6LowpanClass {
@@ -43,7 +44,7 @@ struct _NMSetting6LowpanClass {
 G_DEFINE_TYPE(NMSetting6Lowpan, nm_setting_6lowpan, NM_TYPE_SETTING)
 
 #define NM_SETTING_6LOWPAN_GET_PRIVATE(o) \
-    (G_TYPE_INSTANCE_GET_PRIVATE((o), NM_TYPE_SETTING_6LOWPAN, NMSetting6LowpanPrivate))
+    _NM_GET_PRIVATE(o, NMSetting6Lowpan, NM_IS_SETTING_6LOWPAN, NMSetting)
 
 /*****************************************************************************/
 
@@ -156,8 +157,6 @@ nm_setting_6lowpan_class_init(NMSetting6LowpanClass *klass)
     NMSettingClass *setting_class       = NM_SETTING_CLASS(klass);
     GArray         *properties_override = _nm_sett_info_property_override_create_array();
 
-    g_type_class_add_private(klass, sizeof(NMSetting6LowpanPrivate));
-
     object_class->get_property = _nm_setting_property_get_property_direct;
     object_class->set_property = _nm_setting_property_set_property_direct;
 
@@ -185,5 +184,5 @@ nm_setting_6lowpan_class_init(NMSetting6LowpanClass *klass)
                              NM_META_SETTING_TYPE_6LOWPAN,
                              NULL,
                              properties_override,
-                             NM_SETT_INFO_PRIVATE_OFFSET_FROM_CLASS);
+                             G_STRUCT_OFFSET(NMSetting6Lowpan, _priv));
 }
diff --git a/src/libnm-core-impl/nm-setting-8021x.c b/src/libnm-core-impl/nm-setting-8021x.c
index 626673e87e..cf12b6f53b 100644
--- a/src/libnm-core-impl/nm-setting-8021x.c
+++ b/src/libnm-core-impl/nm-setting-8021x.c
@@ -189,20 +189,18 @@ typedef struct {
  * IEEE 802.1x Authentication Settings
  */
 struct _NMSetting8021x {
-    NMSetting parent;
-    /* In the past, this struct was public API. Preserve ABI! */
+    NMSetting             parent;
+    NMSetting8021xPrivate _priv;
 };
 
 struct _NMSetting8021xClass {
     NMSettingClass parent;
-    /* In the past, this struct was public API. Preserve ABI! */
-    gpointer padding[4];
 };
 
 G_DEFINE_TYPE(NMSetting8021x, nm_setting_802_1x, NM_TYPE_SETTING)
 
 #define NM_SETTING_802_1X_GET_PRIVATE(o) \
-    (G_TYPE_INSTANCE_GET_PRIVATE((o), NM_TYPE_SETTING_802_1X, NMSetting8021xPrivate))
+    _NM_GET_PRIVATE(o, NMSetting8021x, NM_IS_SETTING_802_1X, NMSetting)
 
 /*****************************************************************************/
 
@@ -3201,8 +3199,6 @@ nm_setting_802_1x_class_init(NMSetting8021xClass *klass)
     NMSettingClass *setting_class       = NM_SETTING_CLASS(klass);
     GArray         *properties_override = _nm_sett_info_property_override_create_array();
 
-    g_type_class_add_private(klass, sizeof(NMSetting8021xPrivate));
-
     object_class->get_property = get_property;
     object_class->set_property = set_property;
     object_class->finalize     = finalize;
@@ -4352,5 +4348,5 @@ nm_setting_802_1x_class_init(NMSetting8021xClass *klass)
                              NM_META_SETTING_TYPE_802_1X,
                              NULL,
                              properties_override,
-                             NM_SETT_INFO_PRIVATE_OFFSET_FROM_CLASS);
+                             G_STRUCT_OFFSET(NMSetting8021x, _priv));
 }
diff --git a/src/libnm-core-impl/nm-setting-adsl.c b/src/libnm-core-impl/nm-setting-adsl.c
index ca2913898a..3336c27471 100644
--- a/src/libnm-core-impl/nm-setting-adsl.c
+++ b/src/libnm-core-impl/nm-setting-adsl.c
@@ -46,20 +46,18 @@ typedef struct {
  * ADSL Settings
  */
 struct _NMSettingAdsl {
-    NMSetting parent;
-    /* In the past, this struct was public API. Preserve ABI! */
+    NMSetting            parent;
+    NMSettingAdslPrivate _priv;
 };
 
 struct _NMSettingAdslClass {
     NMSettingClass parent;
-    /* In the past, this struct was public API. Preserve ABI! */
-    gpointer padding[4];
 };
 
 G_DEFINE_TYPE(NMSettingAdsl, nm_setting_adsl, NM_TYPE_SETTING)
 
 #define NM_SETTING_ADSL_GET_PRIVATE(o) \
-    (G_TYPE_INSTANCE_GET_PRIVATE((o), NM_TYPE_SETTING_ADSL, NMSettingAdslPrivate))
+    _NM_GET_PRIVATE(o, NMSettingAdsl, NM_IS_SETTING_ADSL, NMSetting)
 
 /*****************************************************************************/
 
@@ -267,8 +265,6 @@ nm_setting_adsl_class_init(NMSettingAdslClass *klass)
     NMSettingClass *setting_class       = NM_SETTING_CLASS(klass);
     GArray         *properties_override = _nm_sett_info_property_override_create_array();
 
-    g_type_class_add_private(klass, sizeof(NMSettingAdslPrivate));
-
     object_class->get_property = _nm_setting_property_get_property_direct;
     object_class->set_property = _nm_setting_property_set_property_direct;
 
@@ -380,5 +376,5 @@ nm_setting_adsl_class_init(NMSettingAdslClass *klass)
                              NM_META_SETTING_TYPE_ADSL,
                              NULL,
                              properties_override,
-                             NM_SETT_INFO_PRIVATE_OFFSET_FROM_CLASS);
+                             G_STRUCT_OFFSET(NMSettingAdsl, _priv));
 }
diff --git a/src/libnm-core-impl/nm-setting-bluetooth.c b/src/libnm-core-impl/nm-setting-bluetooth.c
index f657ff131a..795379f39b 100644
--- a/src/libnm-core-impl/nm-setting-bluetooth.c
+++ b/src/libnm-core-impl/nm-setting-bluetooth.c
@@ -42,20 +42,18 @@ typedef struct {
  * Bluetooth Settings
  */
 struct _NMSettingBluetooth {
-    NMSetting parent;
-    /* In the past, this struct was public API. Preserve ABI! */
+    NMSetting                 parent;
+    NMSettingBluetoothPrivate _priv;
 };
 
 struct _NMSettingBluetoothClass {
     NMSettingClass parent;
-    /* In the past, this struct was public API. Preserve ABI! */
-    gpointer padding[4];
 };
 
 G_DEFINE_TYPE(NMSettingBluetooth, nm_setting_bluetooth, NM_TYPE_SETTING)
 
 #define NM_SETTING_BLUETOOTH_GET_PRIVATE(o) \
-    (G_TYPE_INSTANCE_GET_PRIVATE((o), NM_TYPE_SETTING_BLUETOOTH, NMSettingBluetoothPrivate))
+    _NM_GET_PRIVATE(o, NMSettingBluetooth, NM_IS_SETTING_BLUETOOTH, NMSetting)
 
 /*****************************************************************************/
 
@@ -254,8 +252,6 @@ nm_setting_bluetooth_class_init(NMSettingBluetoothClass *klass)
     NMSettingClass *setting_class       = NM_SETTING_CLASS(klass);
     GArray         *properties_override = _nm_sett_info_property_override_create_array();
 
-    g_type_class_add_private(klass, sizeof(NMSettingBluetoothPrivate));
-
     object_class->get_property = _nm_setting_property_get_property_direct;
     object_class->set_property = _nm_setting_property_set_property_direct;
 
@@ -295,5 +291,5 @@ nm_setting_bluetooth_class_init(NMSettingBluetoothClass *klass)
                              NM_META_SETTING_TYPE_BLUETOOTH,
                              NULL,
                              properties_override,
-                             NM_SETT_INFO_PRIVATE_OFFSET_FROM_CLASS);
+                             G_STRUCT_OFFSET(NMSettingBluetooth, _priv));
 }
diff --git a/src/libnm-core-impl/nm-setting-bond.c b/src/libnm-core-impl/nm-setting-bond.c
index 81c67d51e0..60ae029468 100644
--- a/src/libnm-core-impl/nm-setting-bond.c
+++ b/src/libnm-core-impl/nm-setting-bond.c
@@ -44,20 +44,18 @@ typedef struct {
  * Bonding Settings
  */
 struct _NMSettingBond {
-    NMSetting parent;
-    /* In the past, this struct was public API. Preserve ABI! */
+    NMSetting            parent;
+    NMSettingBondPrivate _priv;
 };
 
 struct _NMSettingBondClass {
     NMSettingClass parent;
-    /* In the past, this struct was public API. Preserve ABI! */
-    gpointer padding[4];
 };
 
 G_DEFINE_TYPE(NMSettingBond, nm_setting_bond, NM_TYPE_SETTING)
 
 #define NM_SETTING_BOND_GET_PRIVATE(o) \
-    (G_TYPE_INSTANCE_GET_PRIVATE((o), NM_TYPE_SETTING_BOND, NMSettingBondPrivate))
+    _NM_GET_PRIVATE(o, NMSettingBond, NM_IS_SETTING_BOND, NMSetting)
 
 /*****************************************************************************/
 
@@ -1322,8 +1320,6 @@ nm_setting_bond_class_init(NMSettingBondClass *klass)
     NMSettingClass *setting_class       = NM_SETTING_CLASS(klass);
     GArray         *properties_override = _nm_sett_info_property_override_create_array();
 
-    g_type_class_add_private(klass, sizeof(NMSettingBondPrivate));
-
     object_class->get_property = get_property;
     object_class->set_property = set_property;
     object_class->finalize     = finalize;
@@ -1380,5 +1376,5 @@ nm_setting_bond_class_init(NMSettingBondClass *klass)
                              NM_META_SETTING_TYPE_BOND,
                              NULL,
                              properties_override,
-                             NM_SETT_INFO_PRIVATE_OFFSET_FROM_CLASS);
+                             G_STRUCT_OFFSET(NMSettingBond, _priv));
 }
diff --git a/src/libnm-core-impl/nm-setting-bridge-port.c b/src/libnm-core-impl/nm-setting-bridge-port.c
index b94a348e8b..d3d779630c 100644
--- a/src/libnm-core-impl/nm-setting-bridge-port.c
+++ b/src/libnm-core-impl/nm-setting-bridge-port.c
@@ -45,20 +45,18 @@ typedef struct {
  * Bridge Port Settings
  */
 struct _NMSettingBridgePort {
-    NMSetting parent;
-    /* In the past, this struct was public API. Preserve ABI! */
+    NMSetting                  parent;
+    NMSettingBridgePortPrivate _priv;
 };
 
 struct _NMSettingBridgePortClass {
     NMSettingClass parent;
-    /* In the past, this struct was public API. Preserve ABI! */
-    gpointer padding[4];
 };
 
 G_DEFINE_TYPE(NMSettingBridgePort, nm_setting_bridge_port, NM_TYPE_SETTING)
 
 #define NM_SETTING_BRIDGE_PORT_GET_PRIVATE(o) \
-    (G_TYPE_INSTANCE_GET_PRIVATE((o), NM_TYPE_SETTING_BRIDGE_PORT, NMSettingBridgePortPrivate))
+    _NM_GET_PRIVATE(o, NMSettingBridgePort, NM_IS_SETTING_BRIDGE_PORT, NMSetting)
 
 /*****************************************************************************/
 
@@ -455,8 +453,6 @@ nm_setting_bridge_port_class_init(NMSettingBridgePortClass *klass)
     NMSettingClass *setting_class       = NM_SETTING_CLASS(klass);
     GArray         *properties_override = _nm_sett_info_property_override_create_array();
 
-    g_type_class_add_private(klass, sizeof(NMSettingBridgePortPrivate));
-
     object_class->get_property = get_property;
     object_class->set_property = set_property;
     object_class->finalize     = finalize;
@@ -579,5 +575,5 @@ nm_setting_bridge_port_class_init(NMSettingBridgePortClass *klass)
                              NM_META_SETTING_TYPE_BRIDGE_PORT,
                              NULL,
                              properties_override,
-                             NM_SETT_INFO_PRIVATE_OFFSET_FROM_CLASS);
+                             G_STRUCT_OFFSET(NMSettingBridgePort, _priv));
 }
diff --git a/src/libnm-core-impl/nm-setting-cdma.c b/src/libnm-core-impl/nm-setting-cdma.c
index c32af6b744..f27f71a24a 100644
--- a/src/libnm-core-impl/nm-setting-cdma.c
+++ b/src/libnm-core-impl/nm-setting-cdma.c
@@ -42,20 +42,18 @@ typedef struct {
  * CDMA-based Mobile Broadband Settings
  */
 struct _NMSettingCdma {
-    NMSetting parent;
-    /* In the past, this struct was public API. Preserve ABI! */
+    NMSetting            parent;
+    NMSettingCdmaPrivate _priv;
 };
 
 struct _NMSettingCdmaClass {
     NMSettingClass parent;
-    /* In the past, this struct was public API. Preserve ABI! */
-    gpointer padding[4];
 };
 
 G_DEFINE_TYPE(NMSettingCdma, nm_setting_cdma, NM_TYPE_SETTING)
 
 #define NM_SETTING_CDMA_GET_PRIVATE(o) \
-    (G_TYPE_INSTANCE_GET_PRIVATE((o), NM_TYPE_SETTING_CDMA, NMSettingCdmaPrivate))
+    _NM_GET_PRIVATE(o, NMSettingCdma, NM_IS_SETTING_CDMA, NMSetting)
 
 /*****************************************************************************/
 
@@ -218,8 +216,6 @@ nm_setting_cdma_class_init(NMSettingCdmaClass *klass)
     NMSettingClass *setting_class       = NM_SETTING_CLASS(klass);
     GArray         *properties_override = _nm_sett_info_property_override_create_array();
 
-    g_type_class_add_private(klass, sizeof(NMSettingCdmaPrivate));
-
     object_class->get_property = _nm_setting_property_get_property_direct;
     object_class->set_property = _nm_setting_property_set_property_direct;
 
@@ -309,5 +305,5 @@ nm_setting_cdma_class_init(NMSettingCdmaClass *klass)
                              NM_META_SETTING_TYPE_CDMA,
                              NULL,
                              properties_override,
-                             NM_SETT_INFO_PRIVATE_OFFSET_FROM_CLASS);
+                             G_STRUCT_OFFSET(NMSettingCdma, _priv));
 }
diff --git a/src/libnm-core-impl/nm-setting-connection.c b/src/libnm-core-impl/nm-setting-connection.c
index 3c26ab5d17..bcd29ce5ee 100644
--- a/src/libnm-core-impl/nm-setting-connection.c
+++ b/src/libnm-core-impl/nm-setting-connection.c
@@ -109,20 +109,18 @@ typedef struct {
  * General Connection Profile Settings
  */
 struct _NMSettingConnection {
-    NMSetting parent;
-    /* In the past, this struct was public API. Preserve ABI! */
+    NMSetting                  parent;
+    NMSettingConnectionPrivate _priv;
 };
 
 struct _NMSettingConnectionClass {
     NMSettingClass parent;
-    /* In the past, this struct was public API. Preserve ABI! */
-    gpointer padding[4];
 };
 
 G_DEFINE_TYPE(NMSettingConnection, nm_setting_connection, NM_TYPE_SETTING)
 
 #define NM_SETTING_CONNECTION_GET_PRIVATE(o) \
-    (G_TYPE_INSTANCE_GET_PRIVATE((o), NM_TYPE_SETTING_CONNECTION, NMSettingConnectionPrivate))
+    _NM_GET_PRIVATE(o, NMSettingConnection, NM_IS_SETTING_CONNECTION, NMSetting)
 
 /*****************************************************************************/
 
@@ -1810,8 +1808,6 @@ nm_setting_connection_class_init(NMSettingConnectionClass *klass)
     NMSettingClass *setting_class       = NM_SETTING_CLASS(klass);
     GArray         *properties_override = _nm_sett_info_property_override_create_array();
 
-    g_type_class_add_private(klass, sizeof(NMSettingConnectionPrivate));
-
     object_class->get_property = get_property;
     object_class->set_property = set_property;
     object_class->finalize     = finalize;
@@ -2779,5 +2775,5 @@ nm_setting_connection_class_init(NMSettingConnectionClass *klass)
                              NM_META_SETTING_TYPE_CONNECTION,
                              NULL,
                              properties_override,
-                             NM_SETT_INFO_PRIVATE_OFFSET_FROM_CLASS);
+                             G_STRUCT_OFFSET(NMSettingConnection, _priv));
 }
diff --git a/src/libnm-core-impl/nm-setting-dcb.c b/src/libnm-core-impl/nm-setting-dcb.c
index d689089124..cca51641a1 100644
--- a/src/libnm-core-impl/nm-setting-dcb.c
+++ b/src/libnm-core-impl/nm-setting-dcb.c
@@ -71,20 +71,17 @@ typedef struct {
  * Data Center Bridging Settings
  */
 struct _NMSettingDcb {
-    NMSetting parent;
-    /* In the past, this struct was public API. Preserve ABI! */
+    NMSetting           parent;
+    NMSettingDcbPrivate _priv;
 };
 
 struct _NMSettingDcbClass {
     NMSettingClass parent;
-    /* In the past, this struct was public API. Preserve ABI! */
-    gpointer padding[4];
 };
 
 G_DEFINE_TYPE(NMSettingDcb, nm_setting_dcb, NM_TYPE_SETTING)
 
-#define NM_SETTING_DCB_GET_PRIVATE(o) \
-    (G_TYPE_INSTANCE_GET_PRIVATE((o), NM_TYPE_SETTING_DCB, NMSettingDcbPrivate))
+#define NM_SETTING_DCB_GET_PRIVATE(o) _NM_GET_PRIVATE(o, NMSettingDcb, NM_IS_SETTING_DCB, NMSetting)
 
 /*****************************************************************************/
 
@@ -845,8 +842,6 @@ nm_setting_dcb_class_init(NMSettingDcbClass *klass)
     NMSettingClass *setting_class       = NM_SETTING_CLASS(klass);
     GArray         *properties_override = _nm_sett_info_property_override_create_array();
 
-    g_type_class_add_private(klass, sizeof(NMSettingDcbPrivate));
-
     object_class->get_property = get_property;
     object_class->set_property = set_property;
 
@@ -1230,5 +1225,5 @@ nm_setting_dcb_class_init(NMSettingDcbClass *klass)
                              NM_META_SETTING_TYPE_DCB,
                              NULL,
                              properties_override,
-                             NM_SETT_INFO_PRIVATE_OFFSET_FROM_CLASS);
+                             G_STRUCT_OFFSET(NMSettingDcb, _priv));
 }
diff --git a/src/libnm-core-impl/nm-setting-dummy.c b/src/libnm-core-impl/nm-setting-dummy.c
index bfc82aeaec..c37b8c08bb 100644
--- a/src/libnm-core-impl/nm-setting-dummy.c
+++ b/src/libnm-core-impl/nm-setting-dummy.c
@@ -28,13 +28,10 @@
  */
 struct _NMSettingDummy {
     NMSetting parent;
-    /* In the past, this struct was public API. Preserve ABI! */
 };
 
 struct _NMSettingDummyClass {
     NMSettingClass parent;
-    /* In the past, this struct was public API. Preserve ABI! */
-    gpointer padding[4];
 };
 
 G_DEFINE_TYPE(NMSettingDummy, nm_setting_dummy, NM_TYPE_SETTING)
diff --git a/src/libnm-core-impl/nm-setting-generic.c b/src/libnm-core-impl/nm-setting-generic.c
index ce212554cf..6623e71faf 100644
--- a/src/libnm-core-impl/nm-setting-generic.c
+++ b/src/libnm-core-impl/nm-setting-generic.c
@@ -23,10 +23,6 @@
 
 /*****************************************************************************/
 
-typedef struct {
-    int dummy;
-} NMSettingGenericPrivate;
-
 /**
  * NMSettingGeneric:
  *
@@ -34,20 +30,14 @@ typedef struct {
  */
 struct _NMSettingGeneric {
     NMSetting parent;
-    /* In the past, this struct was public API. Preserve ABI! */
 };
 
 struct _NMSettingGenericClass {
     NMSettingClass parent;
-    /* In the past, this struct was public API. Preserve ABI! */
-    gpointer padding[4];
 };
 
 G_DEFINE_TYPE(NMSettingGeneric, nm_setting_generic, NM_TYPE_SETTING)
 
-#define NM_SETTING_GENERIC_GET_PRIVATE(o) \
-    (G_TYPE_INSTANCE_GET_PRIVATE((o), NM_TYPE_SETTING_GENERIC, NMSettingGenericPrivate))
-
 /*****************************************************************************/
 
 static void
@@ -72,7 +62,5 @@ nm_setting_generic_class_init(NMSettingGenericClass *klass)
 {
     NMSettingClass *setting_class = NM_SETTING_CLASS(klass);
 
-    g_type_class_add_private(klass, sizeof(NMSettingGenericPrivate));
-
     _nm_setting_class_commit(setting_class, NM_META_SETTING_TYPE_GENERIC, NULL, NULL, 0);
 }
diff --git a/src/libnm-core-impl/nm-setting-gsm.c b/src/libnm-core-impl/nm-setting-gsm.c
index 4dde515a17..3271571902 100644
--- a/src/libnm-core-impl/nm-setting-gsm.c
+++ b/src/libnm-core-impl/nm-setting-gsm.c
@@ -65,20 +65,17 @@ typedef struct {
  * GSM-based Mobile Broadband Settings
  */
 struct _NMSettingGsm {
-    NMSetting parent;
-    /* In the past, this struct was public API. Preserve ABI! */
+    NMSetting           parent;
+    NMSettingGsmPrivate _priv;
 };
 
 struct _NMSettingGsmClass {
     NMSettingClass parent;
-    /* In the past, this struct was public API. Preserve ABI! */
-    gpointer padding[4];
 };
 
 G_DEFINE_TYPE(NMSettingGsm, nm_setting_gsm, NM_TYPE_SETTING)
 
-#define NM_SETTING_GSM_GET_PRIVATE(o) \
-    (G_TYPE_INSTANCE_GET_PRIVATE((o), NM_TYPE_SETTING_GSM, NMSettingGsmPrivate))
+#define NM_SETTING_GSM_GET_PRIVATE(o) _NM_GET_PRIVATE(o, NMSettingGsm, NM_IS_SETTING_GSM, NMSetting)
 
 /*****************************************************************************/
 
@@ -565,8 +562,6 @@ nm_setting_gsm_class_init(NMSettingGsmClass *klass)
     NMSettingClass *setting_class       = NM_SETTING_CLASS(klass);
     GArray         *properties_override = _nm_sett_info_property_override_create_array();
 
-    g_type_class_add_private(klass, sizeof(NMSettingGsmPrivate));
-
     object_class->get_property = _nm_setting_property_get_property_direct;
     object_class->set_property = _nm_setting_property_set_property_direct;
 
@@ -854,5 +849,5 @@ nm_setting_gsm_class_init(NMSettingGsmClass *klass)
                              NM_META_SETTING_TYPE_GSM,
                              NULL,
                              properties_override,
-                             NM_SETT_INFO_PRIVATE_OFFSET_FROM_CLASS);
+                             G_STRUCT_OFFSET(NMSettingGsm, _priv));
 }
diff --git a/src/libnm-core-impl/nm-setting-infiniband.c b/src/libnm-core-impl/nm-setting-infiniband.c
index a0d5578c05..74f8cb5177 100644
--- a/src/libnm-core-impl/nm-setting-infiniband.c
+++ b/src/libnm-core-impl/nm-setting-infiniband.c
@@ -47,20 +47,18 @@ typedef struct {
  * Infiniband Settings
  */
 struct _NMSettingInfiniband {
-    NMSetting parent;
-    /* In the past, this struct was public API. Preserve ABI! */
+    NMSetting                  parent;
+    NMSettingInfinibandPrivate _priv;
 };
 
 struct _NMSettingInfinibandClass {
     NMSettingClass parent;
-    /* In the past, this struct was public API. Preserve ABI! */
-    gpointer padding[4];
 };
 
 G_DEFINE_TYPE(NMSettingInfiniband, nm_setting_infiniband, NM_TYPE_SETTING)
 
 #define NM_SETTING_INFINIBAND_GET_PRIVATE(o) \
-    (G_TYPE_INSTANCE_GET_PRIVATE((o), NM_TYPE_SETTING_INFINIBAND, NMSettingInfinibandPrivate))
+    _NM_GET_PRIVATE(o, NMSettingInfiniband, NM_IS_SETTING_INFINIBAND, NMSetting)
 
 /*****************************************************************************/
 
@@ -332,8 +330,6 @@ nm_setting_infiniband_class_init(NMSettingInfinibandClass *klass)
     NMSettingClass *setting_class       = NM_SETTING_CLASS(klass);
     GArray         *properties_override = _nm_sett_info_property_override_create_array();
 
-    g_type_class_add_private(klass, sizeof(NMSettingInfinibandPrivate));
-
     object_class->get_property = _nm_setting_property_get_property_direct;
     object_class->set_property = _nm_setting_property_set_property_direct;
 
@@ -492,5 +488,5 @@ nm_setting_infiniband_class_init(NMSettingInfinibandClass *klass)
                              NM_META_SETTING_TYPE_INFINIBAND,
                              NULL,
                              properties_override,
-                             NM_SETT_INFO_PRIVATE_OFFSET_FROM_CLASS);
+                             G_STRUCT_OFFSET(NMSettingInfiniband, _priv));
 }
diff --git a/src/libnm-core-impl/nm-setting-ip-config.c b/src/libnm-core-impl/nm-setting-ip-config.c
index ac852d8dec..3184c2747a 100644
--- a/src/libnm-core-impl/nm-setting-ip-config.c
+++ b/src/libnm-core-impl/nm-setting-ip-config.c
@@ -4014,7 +4014,7 @@ _NM_SETTING_IP_CONFIG_GET_PRIVATE(NMSettingIPConfig *self)
 
     klass = NM_SETTING_IP_CONFIG_GET_CLASS(self);
 
-    nm_assert(klass->private_offset < 0);
+    nm_assert(klass->private_offset > 0);
 
     return (gpointer) (((char *) ((gpointer) self)) + klass->private_offset);
 }
diff --git a/src/libnm-core-impl/nm-setting-ip-tunnel.c b/src/libnm-core-impl/nm-setting-ip-tunnel.c
index 2deebf4276..f04842067d 100644
--- a/src/libnm-core-impl/nm-setting-ip-tunnel.c
+++ b/src/libnm-core-impl/nm-setting-ip-tunnel.c
@@ -55,20 +55,18 @@ typedef struct {
  * IP Tunneling Settings
  */
 struct _NMSettingIPTunnel {
-    NMSetting parent;
-    /* In the past, this struct was public API. Preserve ABI! */
+    NMSetting                parent;
+    NMSettingIPTunnelPrivate _priv;
 };
 
 struct _NMSettingIPTunnelClass {
     NMSettingClass parent;
-    /* In the past, this struct was public API. Preserve ABI! */
-    gpointer padding[4];
 };
 
 G_DEFINE_TYPE(NMSettingIPTunnel, nm_setting_ip_tunnel, NM_TYPE_SETTING)
 
 #define NM_SETTING_IP_TUNNEL_GET_PRIVATE(o) \
-    (G_TYPE_INSTANCE_GET_PRIVATE((o), NM_TYPE_SETTING_IP_TUNNEL, NMSettingIPTunnelPrivate))
+    _NM_GET_PRIVATE(o, NMSettingIPTunnel, NM_IS_SETTING_IP_TUNNEL, NMSetting)
 
 /*****************************************************************************/
 
@@ -566,8 +564,6 @@ nm_setting_ip_tunnel_class_init(NMSettingIPTunnelClass *klass)
     NMSettingClass *setting_class       = NM_SETTING_CLASS(klass);
     GArray         *properties_override = _nm_sett_info_property_override_create_array();
 
-    g_type_class_add_private(klass, sizeof(NMSettingIPTunnelPrivate));
-
     object_class->get_property = _nm_setting_property_get_property_direct;
     object_class->set_property = _nm_setting_property_set_property_direct;
 
@@ -861,5 +857,5 @@ nm_setting_ip_tunnel_class_init(NMSettingIPTunnelClass *klass)
                              NM_META_SETTING_TYPE_IP_TUNNEL,
                              NULL,
                              properties_override,
-                             NM_SETT_INFO_PRIVATE_OFFSET_FROM_CLASS);
+                             G_STRUCT_OFFSET(NMSettingIPTunnel, _priv));
 }
diff --git a/src/libnm-core-impl/nm-setting-ip4-config.c b/src/libnm-core-impl/nm-setting-ip4-config.c
index c066f8a222..e4914d0244 100644
--- a/src/libnm-core-impl/nm-setting-ip4-config.c
+++ b/src/libnm-core-impl/nm-setting-ip4-config.c
@@ -56,20 +56,18 @@ typedef struct {
  * IPv4 Settings
  */
 struct _NMSettingIP4Config {
-    NMSettingIPConfig parent;
-    /* In the past, this struct was public API. Preserve ABI! */
+    NMSettingIPConfig         parent;
+    NMSettingIP4ConfigPrivate _priv;
 };
 
 struct _NMSettingIP4ConfigClass {
     NMSettingIPConfigClass parent;
-    /* In the past, this struct was public API. Preserve ABI! */
-    gpointer padding[4];
 };
 
 G_DEFINE_TYPE(NMSettingIP4Config, nm_setting_ip4_config, NM_TYPE_SETTING_IP_CONFIG)
 
 #define NM_SETTING_IP4_CONFIG_GET_PRIVATE(o) \
-    (G_TYPE_INSTANCE_GET_PRIVATE((o), NM_TYPE_SETTING_IP4_CONFIG, NMSettingIP4ConfigPrivate))
+    _NM_GET_PRIVATE(o, NMSettingIP4Config, NM_IS_SETTING_IP4_CONFIG, NMSettingIPConfig, NMSetting)
 
 /*****************************************************************************/
 
@@ -616,14 +614,12 @@ nm_setting_ip4_config_class_init(NMSettingIP4ConfigClass *klass)
     NMSettingIPConfigClass *setting_ip_config_class = NM_SETTING_IP_CONFIG_CLASS(klass);
     GArray *properties_override = _nm_sett_info_property_override_create_array_ip_config(AF_INET);
 
-    g_type_class_add_private(klass, sizeof(NMSettingIP4ConfigPrivate));
-
     object_class->get_property = _nm_setting_property_get_property_direct;
     object_class->set_property = _nm_setting_property_set_property_direct;
 
     setting_class->verify = verify;
 
-    setting_ip_config_class->private_offset = g_type_class_get_instance_private_offset(klass);
+    setting_ip_config_class->private_offset = G_STRUCT_OFFSET(NMSettingIP4Config, _priv);
     setting_ip_config_class->is_ipv4        = TRUE;
     setting_ip_config_class->addr_family    = AF_INET;
 
@@ -1317,5 +1313,5 @@ nm_setting_ip4_config_class_init(NMSettingIP4ConfigClass *klass)
                              NM_META_SETTING_TYPE_IP4_CONFIG,
                              NULL,
                              properties_override,
-                             setting_ip_config_class->private_offset);
+                             G_STRUCT_OFFSET(NMSettingIP4Config, _priv));
 }
diff --git a/src/libnm-core-impl/nm-setting-ip6-config.c b/src/libnm-core-impl/nm-setting-ip6-config.c
index 9e93336539..272523b143 100644
--- a/src/libnm-core-impl/nm-setting-ip6-config.c
+++ b/src/libnm-core-impl/nm-setting-ip6-config.c
@@ -65,20 +65,18 @@ typedef struct {
  * IPv6 Settings
  */
 struct _NMSettingIP6Config {
-    NMSettingIPConfig parent;
-    /* In the past, this struct was public API. Preserve ABI! */
+    NMSettingIPConfig         parent;
+    NMSettingIP6ConfigPrivate _priv;
 };
 
 struct _NMSettingIP6ConfigClass {
     NMSettingIPConfigClass parent;
-    /* In the past, this struct was public API. Preserve ABI! */
-    gpointer padding[4];
 };
 
 G_DEFINE_TYPE(NMSettingIP6Config, nm_setting_ip6_config, NM_TYPE_SETTING_IP_CONFIG)
 
 #define NM_SETTING_IP6_CONFIG_GET_PRIVATE(o) \
-    (G_TYPE_INSTANCE_GET_PRIVATE((o), NM_TYPE_SETTING_IP6_CONFIG, NMSettingIP6ConfigPrivate))
+    _NM_GET_PRIVATE(o, NMSettingIP6Config, NM_IS_SETTING_IP6_CONFIG, NMSettingIPConfig, NMSetting)
 
 /*****************************************************************************/
 
@@ -628,14 +626,12 @@ nm_setting_ip6_config_class_init(NMSettingIP6ConfigClass *klass)
     NMSettingIPConfigClass *setting_ip_config_class = NM_SETTING_IP_CONFIG_CLASS(klass);
     GArray *properties_override = _nm_sett_info_property_override_create_array_ip_config(AF_INET6);
 
-    g_type_class_add_private(klass, sizeof(NMSettingIP6ConfigPrivate));
-
     object_class->get_property = _nm_setting_property_get_property_direct;
     object_class->set_property = _nm_setting_property_set_property_direct;
 
     setting_class->verify = verify;
 
-    setting_ip_config_class->private_offset = g_type_class_get_instance_private_offset(klass);
+    setting_ip_config_class->private_offset = G_STRUCT_OFFSET(NMSettingIP6Config, _priv);
     setting_ip_config_class->is_ipv4        = FALSE;
     setting_ip_config_class->addr_family    = AF_INET6;
 
@@ -1444,5 +1440,5 @@ nm_setting_ip6_config_class_init(NMSettingIP6ConfigClass *klass)
                              NM_META_SETTING_TYPE_IP6_CONFIG,
                              NULL,
                              properties_override,
-                             setting_ip_config_class->private_offset);
+                             G_STRUCT_OFFSET(NMSettingIP6Config, _priv));
 }
diff --git a/src/libnm-core-impl/nm-setting-macsec.c b/src/libnm-core-impl/nm-setting-macsec.c
index bf48f049df..ba15d45568 100644
--- a/src/libnm-core-impl/nm-setting-macsec.c
+++ b/src/libnm-core-impl/nm-setting-macsec.c
@@ -55,20 +55,18 @@ typedef struct {
  * MACSec Settings
  */
 struct _NMSettingMacsec {
-    NMSetting parent;
-    /* In the past, this struct was public API. Preserve ABI! */
+    NMSetting              parent;
+    NMSettingMacsecPrivate _priv;
 };
 
 struct _NMSettingMacsecClass {
     NMSettingClass parent;
-    /* In the past, this struct was public API. Preserve ABI! */
-    gpointer padding[4];
 };
 
 G_DEFINE_TYPE(NMSettingMacsec, nm_setting_macsec, NM_TYPE_SETTING)
 
 #define NM_SETTING_MACSEC_GET_PRIVATE(o) \
-    (G_TYPE_INSTANCE_GET_PRIVATE((o), NM_TYPE_SETTING_MACSEC, NMSettingMacsecPrivate))
+    _NM_GET_PRIVATE(o, NMSettingMacsec, NM_IS_SETTING_MACSEC, NMSetting)
 
 /*****************************************************************************/
 
@@ -436,8 +434,6 @@ nm_setting_macsec_class_init(NMSettingMacsecClass *klass)
     NMSettingClass *setting_class       = NM_SETTING_CLASS(klass);
     GArray         *properties_override = _nm_sett_info_property_override_create_array();
 
-    g_type_class_add_private(klass, sizeof(NMSettingMacsecPrivate));
-
     object_class->get_property = _nm_setting_property_get_property_direct;
     object_class->set_property = _nm_setting_property_set_property_direct;
 
@@ -604,5 +600,5 @@ nm_setting_macsec_class_init(NMSettingMacsecClass *klass)
                              NM_META_SETTING_TYPE_MACSEC,
                              NULL,
                              properties_override,
-                             NM_SETT_INFO_PRIVATE_OFFSET_FROM_CLASS);
+                             G_STRUCT_OFFSET(NMSettingMacsec, _priv));
 }
diff --git a/src/libnm-core-impl/nm-setting-macvlan.c b/src/libnm-core-impl/nm-setting-macvlan.c
index d26a80862b..1f808c3cc0 100644
--- a/src/libnm-core-impl/nm-setting-macvlan.c
+++ b/src/libnm-core-impl/nm-setting-macvlan.c
@@ -40,20 +40,18 @@ typedef struct {
  * MAC VLAN Settings
  */
 struct _NMSettingMacvlan {
-    NMSetting parent;
-    /* In the past, this struct was public API. Preserve ABI! */
+    NMSetting               parent;
+    NMSettingMacvlanPrivate _priv;
 };
 
 struct _NMSettingMacvlanClass {
     NMSettingClass parent;
-    /* In the past, this struct was public API. Preserve ABI! */
-    gpointer padding[4];
 };
 
 G_DEFINE_TYPE(NMSettingMacvlan, nm_setting_macvlan, NM_TYPE_SETTING)
 
 #define NM_SETTING_MACVLAN_GET_PRIVATE(o) \
-    (G_TYPE_INSTANCE_GET_PRIVATE((o), NM_TYPE_SETTING_MACVLAN, NMSettingMacvlanPrivate))
+    _NM_GET_PRIVATE(o, NMSettingMacvlan, NM_IS_SETTING_MACVLAN, NMSetting)
 
 /*****************************************************************************/
 
@@ -207,8 +205,6 @@ nm_setting_macvlan_class_init(NMSettingMacvlanClass *klass)
     NMSettingClass *setting_class       = NM_SETTING_CLASS(klass);
     GArray         *properties_override = _nm_sett_info_property_override_create_array();
 
-    g_type_class_add_private(klass, sizeof(NMSettingMacvlanPrivate));
-
     object_class->get_property = _nm_setting_property_get_property_direct;
     object_class->set_property = _nm_setting_property_set_property_direct;
 
@@ -289,5 +285,5 @@ nm_setting_macvlan_class_init(NMSettingMacvlanClass *klass)
                              NM_META_SETTING_TYPE_MACVLAN,
                              NULL,
                              properties_override,
-                             NM_SETT_INFO_PRIVATE_OFFSET_FROM_CLASS);
+                             G_STRUCT_OFFSET(NMSettingMacvlan, _priv));
 }
diff --git a/src/libnm-core-impl/nm-setting-olpc-mesh.c b/src/libnm-core-impl/nm-setting-olpc-mesh.c
index fe6d3842e8..1b13d99a2d 100644
--- a/src/libnm-core-impl/nm-setting-olpc-mesh.c
+++ b/src/libnm-core-impl/nm-setting-olpc-mesh.c
@@ -39,20 +39,18 @@ typedef struct {
  * OLPC Wireless Mesh Settings
  */
 struct _NMSettingOlpcMesh {
-    NMSetting parent;
-    /* In the past, this struct was public API. Preserve ABI! */
+    NMSetting                parent;
+    NMSettingOlpcMeshPrivate _priv;
 };
 
 struct _NMSettingOlpcMeshClass {
     NMSettingClass parent;
-    /* In the past, this struct was public API. Preserve ABI! */
-    gpointer padding[4];
 };
 
 G_DEFINE_TYPE(NMSettingOlpcMesh, nm_setting_olpc_mesh, NM_TYPE_SETTING)
 
 #define NM_SETTING_OLPC_MESH_GET_PRIVATE(o) \
-    (G_TYPE_INSTANCE_GET_PRIVATE((o), NM_TYPE_SETTING_OLPC_MESH, NMSettingOlpcMeshPrivate))
+    _NM_GET_PRIVATE(o, NMSettingOlpcMesh, NM_IS_SETTING_OLPC_MESH, NMSetting)
 
 /*****************************************************************************/
 
@@ -171,8 +169,6 @@ nm_setting_olpc_mesh_class_init(NMSettingOlpcMeshClass *klass)
     NMSettingClass *setting_class       = NM_SETTING_CLASS(klass);
     GArray         *properties_override = _nm_sett_info_property_override_create_array();
 
-    g_type_class_add_private(klass, sizeof(NMSettingOlpcMeshPrivate));
-
     object_class->get_property = _nm_setting_property_get_property_direct;
     object_class->set_property = _nm_setting_property_set_property_direct;
 
@@ -231,5 +227,5 @@ nm_setting_olpc_mesh_class_init(NMSettingOlpcMeshClass *klass)
                              NM_META_SETTING_TYPE_OLPC_MESH,
                              NULL,
                              properties_override,
-                             NM_SETT_INFO_PRIVATE_OFFSET_FROM_CLASS);
+                             G_STRUCT_OFFSET(NMSettingOlpcMesh, _priv));
 }
diff --git a/src/libnm-core-impl/nm-setting-ppp.c b/src/libnm-core-impl/nm-setting-ppp.c
index a9d2b9a2c1..2ac276b46a 100644
--- a/src/libnm-core-impl/nm-setting-ppp.c
+++ b/src/libnm-core-impl/nm-setting-ppp.c
@@ -68,20 +68,17 @@ typedef struct {
  * Point-to-Point Protocol Settings
  */
 struct _NMSettingPpp {
-    NMSetting parent;
-    /* In the past, this struct was public API. Preserve ABI! */
+    NMSetting           parent;
+    NMSettingPppPrivate _priv;
 };
 
 struct _NMSettingPppClass {
     NMSettingClass parent;
-    /* In the past, this struct was public API. Preserve ABI! */
-    gpointer padding[4];
 };
 
 G_DEFINE_TYPE(NMSettingPpp, nm_setting_ppp, NM_TYPE_SETTING)
 
-#define NM_SETTING_PPP_GET_PRIVATE(o) \
-    (G_TYPE_INSTANCE_GET_PRIVATE((o), NM_TYPE_SETTING_PPP, NMSettingPppPrivate))
+#define NM_SETTING_PPP_GET_PRIVATE(o) _NM_GET_PRIVATE(o, NMSettingPpp, NM_IS_SETTING_PPP, NMSetting)
 
 /*****************************************************************************/
 
@@ -402,8 +399,6 @@ nm_setting_ppp_class_init(NMSettingPppClass *klass)
     NMSettingClass *setting_class       = NM_SETTING_CLASS(klass);
     GArray         *properties_override = _nm_sett_info_property_override_create_array();
 
-    g_type_class_add_private(klass, sizeof(NMSettingPppPrivate));
-
     object_class->get_property = _nm_setting_property_get_property_direct;
     object_class->set_property = _nm_setting_property_set_property_direct;
 
@@ -698,5 +693,5 @@ nm_setting_ppp_class_init(NMSettingPppClass *klass)
                              NM_META_SETTING_TYPE_PPP,
                              NULL,
                              properties_override,
-                             NM_SETT_INFO_PRIVATE_OFFSET_FROM_CLASS);
+                             G_STRUCT_OFFSET(NMSettingPpp, _priv));
 }
diff --git a/src/libnm-core-impl/nm-setting-pppoe.c b/src/libnm-core-impl/nm-setting-pppoe.c
index 5c4f3c28a1..6c2e1e86a3 100644
--- a/src/libnm-core-impl/nm-setting-pppoe.c
+++ b/src/libnm-core-impl/nm-setting-pppoe.c
@@ -43,20 +43,18 @@ typedef struct {
  * PPP-over-Ethernet Settings
  */
 struct _NMSettingPppoe {
-    NMSetting parent;
-    /* In the past, this struct was public API. Preserve ABI! */
+    NMSetting             parent;
+    NMSettingPppoePrivate _priv;
 };
 
 struct _NMSettingPppoeClass {
     NMSettingClass parent;
-    /* In the past, this struct was public API. Preserve ABI! */
-    gpointer padding[4];
 };
 
 G_DEFINE_TYPE(NMSettingPppoe, nm_setting_pppoe, NM_TYPE_SETTING)
 
 #define NM_SETTING_PPPOE_GET_PRIVATE(o) \
-    (G_TYPE_INSTANCE_GET_PRIVATE((o), NM_TYPE_SETTING_PPPOE, NMSettingPppoePrivate))
+    _NM_GET_PRIVATE(o, NMSettingPppoe, NM_IS_SETTING_PPPOE, NMSetting)
 
 /*****************************************************************************/
 
@@ -220,8 +218,6 @@ nm_setting_pppoe_class_init(NMSettingPppoeClass *klass)
     NMSettingClass *setting_class       = NM_SETTING_CLASS(klass);
     GArray         *properties_override = _nm_sett_info_property_override_create_array();
 
-    g_type_class_add_private(klass, sizeof(NMSettingPppoePrivate));
-
     object_class->get_property = _nm_setting_property_get_property_direct;
     object_class->set_property = _nm_setting_property_set_property_direct;
 
@@ -306,5 +302,5 @@ nm_setting_pppoe_class_init(NMSettingPppoeClass *klass)
                              NM_META_SETTING_TYPE_PPPOE,
                              NULL,
                              properties_override,
-                             NM_SETT_INFO_PRIVATE_OFFSET_FROM_CLASS);
+                             G_STRUCT_OFFSET(NMSettingPppoe, _priv));
 }
diff --git a/src/libnm-core-impl/nm-setting-private.h b/src/libnm-core-impl/nm-setting-private.h
index fff6c1ccc5..2567413233 100644
--- a/src/libnm-core-impl/nm-setting-private.h
+++ b/src/libnm-core-impl/nm-setting-private.h
@@ -80,6 +80,8 @@ void _nm_connection_private_clear(NMConnectionPrivate *priv);
 
 /*****************************************************************************/
 
+struct _NMSettingPrivate;
+
 /**
  * NMSetting:
  *
@@ -87,15 +89,13 @@ void _nm_connection_private_clear(NMConnectionPrivate *priv);
  * It should only be accessed through the functions described below.
  */
 struct _NMSetting {
-    GObject parent;
-    /* In the past, this struct was public API. Preserve ABI! */
+    GObject                   parent;
+    struct _NMSettingPrivate *_priv;
 };
 
 struct _NMSettingClass {
     GObjectClass parent;
 
-    /* In the past, this struct was public API. Preserve ABI! */
-
     int (*verify)(NMSetting *setting, NMConnection *connection, GError **error);
 
     gboolean (*verify_secrets)(NMSetting *setting, NMConnection *connection, GError **error);
@@ -120,8 +120,6 @@ struct _NMSettingClass {
                               NMSettingClearSecretsWithFlagsFn func,
                               gpointer                         user_data);
 
-    void (*padding_1)(void);
-
     void (*duplicate_copy_properties)(const struct _NMSettInfoSetting *sett_info,
                                       NMSetting                       *src,
                                       NMSetting                       *dst);
@@ -158,30 +156,13 @@ struct _NMSettingClass {
  */
 struct _NMSettingIPConfig {
     NMSetting parent;
-    /* In the past, this struct was public API. Preserve ABI! */
 };
 
 struct _NMSettingIPConfigClass {
     NMSettingClass parent;
-
-    /* In the past, this struct was public API. Preserve ABI! */
-
-    union {
-        gpointer _dummy1;
-        int      private_offset;
-    };
-
-    union {
-        gpointer _dummy2;
-        gint8    addr_family;
-    };
-
-    union {
-        gpointer _dummy3;
-        bool     is_ipv4;
-    };
-
-    gpointer padding[5];
+    int            private_offset;
+    gint8          addr_family;
+    bool           is_ipv4;
 };
 
 typedef struct {
diff --git a/src/libnm-core-impl/nm-setting-proxy.c b/src/libnm-core-impl/nm-setting-proxy.c
index 8b91210b9b..62ba5050a4 100644
--- a/src/libnm-core-impl/nm-setting-proxy.c
+++ b/src/libnm-core-impl/nm-setting-proxy.c
@@ -41,19 +41,18 @@ typedef struct {
  * WWW Proxy Settings
  */
 struct _NMSettingProxy {
-    NMSetting parent;
+    NMSetting             parent;
+    NMSettingProxyPrivate _priv;
 };
 
 struct _NMSettingProxyClass {
     NMSettingClass parent;
-
-    gpointer padding[4];
 };
 
 G_DEFINE_TYPE(NMSettingProxy, nm_setting_proxy, NM_TYPE_SETTING)
 
 #define NM_SETTING_PROXY_GET_PRIVATE(o) \
-    (G_TYPE_INSTANCE_GET_PRIVATE((o), NM_TYPE_SETTING_PROXY, NMSettingProxyPrivate))
+    _NM_GET_PRIVATE(o, NMSettingProxy, NM_IS_SETTING_PROXY, NMSetting)
 
 /*****************************************************************************/
 
@@ -233,8 +232,6 @@ nm_setting_proxy_class_init(NMSettingProxyClass *klass)
     NMSettingClass *setting_class       = NM_SETTING_CLASS(klass);
     GArray         *properties_override = _nm_sett_info_property_override_create_array();
 
-    g_type_class_add_private(klass, sizeof(NMSettingProxyPrivate));
-
     object_class->get_property = _nm_setting_property_get_property_direct;
     object_class->set_property = _nm_setting_property_set_property_direct;
 
@@ -350,5 +347,5 @@ nm_setting_proxy_class_init(NMSettingProxyClass *klass)
                              NM_META_SETTING_TYPE_PROXY,
                              NULL,
                              properties_override,
-                             NM_SETT_INFO_PRIVATE_OFFSET_FROM_CLASS);
+                             G_STRUCT_OFFSET(NMSettingProxy, _priv));
 }
diff --git a/src/libnm-core-impl/nm-setting-serial.c b/src/libnm-core-impl/nm-setting-serial.c
index 6fe3e487d1..ab2a8319e0 100644
--- a/src/libnm-core-impl/nm-setting-serial.c
+++ b/src/libnm-core-impl/nm-setting-serial.c
@@ -42,20 +42,18 @@ typedef struct {
  * Serial Link Settings
  */
 struct _NMSettingSerial {
-    NMSetting parent;
-    /* In the past, this struct was public API. Preserve ABI! */
+    NMSetting              parent;
+    NMSettingSerialPrivate _priv;
 };
 
 struct _NMSettingSerialClass {
     NMSettingClass parent;
-    /* In the past, this struct was public API. Preserve ABI! */
-    gpointer padding[4];
 };
 
 G_DEFINE_TYPE(NMSettingSerial, nm_setting_serial, NM_TYPE_SETTING)
 
 #define NM_SETTING_SERIAL_GET_PRIVATE(o) \
-    (G_TYPE_INSTANCE_GET_PRIVATE((o), NM_TYPE_SETTING_SERIAL, NMSettingSerialPrivate))
+    _NM_GET_PRIVATE(o, NMSettingSerial, NM_IS_SETTING_SERIAL, NMSetting)
 
 /*****************************************************************************/
 
@@ -226,8 +224,6 @@ nm_setting_serial_class_init(NMSettingSerialClass *klass)
     NMSettingClass *setting_class       = NM_SETTING_CLASS(klass);
     GArray         *properties_override = _nm_sett_info_property_override_create_array();
 
-    g_type_class_add_private(klass, sizeof(NMSettingSerialPrivate));
-
     object_class->get_property = get_property;
     object_class->set_property = set_property;
 
@@ -341,5 +337,5 @@ nm_setting_serial_class_init(NMSettingSerialClass *klass)
                              NM_META_SETTING_TYPE_SERIAL,
                              NULL,
                              properties_override,
-                             NM_SETT_INFO_PRIVATE_OFFSET_FROM_CLASS);
+                             G_STRUCT_OFFSET(NMSettingSerial, _priv));
 }
diff --git a/src/libnm-core-impl/nm-setting-team-port.c b/src/libnm-core-impl/nm-setting-team-port.c
index 816d85d9ff..6c9a5a7789 100644
--- a/src/libnm-core-impl/nm-setting-team-port.c
+++ b/src/libnm-core-impl/nm-setting-team-port.c
@@ -41,20 +41,18 @@ typedef struct {
  * Team Port Settings
  */
 struct _NMSettingTeamPort {
-    NMSetting parent;
-    /* In the past, this struct was public API. Preserve ABI! */
+    NMSetting                parent;
+    NMSettingTeamPortPrivate _priv;
 };
 
 struct _NMSettingTeamPortClass {
     NMSettingClass parent;
-    /* In the past, this struct was public API. Preserve ABI! */
-    gpointer padding[4];
 };
 
 G_DEFINE_TYPE(NMSettingTeamPort, nm_setting_team_port, NM_TYPE_SETTING)
 
 #define NM_SETTING_TEAM_PORT_GET_PRIVATE(o) \
-    (G_TYPE_INSTANCE_GET_PRIVATE((o), NM_TYPE_SETTING_TEAM_PORT, NMSettingTeamPortPrivate))
+    _NM_GET_PRIVATE(o, NMSettingTeamPort, NM_IS_SETTING_TEAM_PORT, NMSetting)
 
 /*****************************************************************************/
 
@@ -532,8 +530,6 @@ nm_setting_team_port_class_init(NMSettingTeamPortClass *klass)
     NMSettingClass *setting_class       = NM_SETTING_CLASS(klass);
     GArray         *properties_override = _nm_sett_info_property_override_create_array();
 
-    g_type_class_add_private(klass, sizeof(NMSettingTeamPortPrivate));
-
     object_class->get_property = get_property;
     object_class->set_property = set_property;
     object_class->finalize     = finalize;
@@ -702,5 +698,5 @@ nm_setting_team_port_class_init(NMSettingTeamPortClass *klass)
                              NM_META_SETTING_TYPE_TEAM_PORT,
                              NULL,
                              properties_override,
-                             NM_SETT_INFO_PRIVATE_OFFSET_FROM_CLASS);
+                             G_STRUCT_OFFSET(NMSettingTeamPort, _priv));
 }
diff --git a/src/libnm-core-impl/nm-setting-team.c b/src/libnm-core-impl/nm-setting-team.c
index 83de8b6fe0..5cc63870fc 100644
--- a/src/libnm-core-impl/nm-setting-team.c
+++ b/src/libnm-core-impl/nm-setting-team.c
@@ -745,20 +745,18 @@ typedef struct {
  * Teaming Settings
  */
 struct _NMSettingTeam {
-    NMSetting parent;
-    /* In the past, this struct was public API. Preserve ABI! */
+    NMSetting            parent;
+    NMSettingTeamPrivate _priv;
 };
 
 struct _NMSettingTeamClass {
     NMSettingClass parent;
-    /* In the past, this struct was public API. Preserve ABI! */
-    gpointer padding[4];
 };
 
 G_DEFINE_TYPE(NMSettingTeam, nm_setting_team, NM_TYPE_SETTING)
 
 #define NM_SETTING_TEAM_GET_PRIVATE(o) \
-    (G_TYPE_INSTANCE_GET_PRIVATE((o), NM_TYPE_SETTING_TEAM, NMSettingTeamPrivate))
+    _NM_GET_PRIVATE(o, NMSettingTeam, NM_IS_SETTING_TEAM, NMSetting)
 
 /*****************************************************************************/
 
@@ -1498,8 +1496,6 @@ nm_setting_team_class_init(NMSettingTeamClass *klass)
     NMSettingClass *setting_class       = NM_SETTING_CLASS(klass);
     GArray         *properties_override = _nm_sett_info_property_override_create_array();
 
-    g_type_class_add_private(klass, sizeof(NMSettingTeamPrivate));
-
     object_class->get_property = get_property;
     object_class->set_property = set_property;
     object_class->finalize     = finalize;
@@ -1842,5 +1838,5 @@ nm_setting_team_class_init(NMSettingTeamClass *klass)
                              NM_META_SETTING_TYPE_TEAM,
                              NULL,
                              properties_override,
-                             NM_SETT_INFO_PRIVATE_OFFSET_FROM_CLASS);
+                             G_STRUCT_OFFSET(NMSettingTeam, _priv));
 }
diff --git a/src/libnm-core-impl/nm-setting-tun.c b/src/libnm-core-impl/nm-setting-tun.c
index ec095155ee..a6060850f9 100644
--- a/src/libnm-core-impl/nm-setting-tun.c
+++ b/src/libnm-core-impl/nm-setting-tun.c
@@ -46,20 +46,17 @@ typedef struct {
  * Tunnel Settings
  */
 struct _NMSettingTun {
-    NMSetting parent;
-    /* In the past, this struct was public API. Preserve ABI! */
+    NMSetting           parent;
+    NMSettingTunPrivate _priv;
 };
 
 struct _NMSettingTunClass {
     NMSettingClass parent;
-    /* In the past, this struct was public API. Preserve ABI! */
-    gpointer padding[4];
 };
 
 G_DEFINE_TYPE(NMSettingTun, nm_setting_tun, NM_TYPE_SETTING)
 
-#define NM_SETTING_TUN_GET_PRIVATE(o) \
-    (G_TYPE_INSTANCE_GET_PRIVATE((o), NM_TYPE_SETTING_TUN, NMSettingTunPrivate))
+#define NM_SETTING_TUN_GET_PRIVATE(o) _NM_GET_PRIVATE(o, NMSettingTun, NM_IS_SETTING_TUN, NMSetting)
 
 /*****************************************************************************/
 
@@ -223,8 +220,6 @@ nm_setting_tun_class_init(NMSettingTunClass *klass)
     NMSettingClass *setting_class       = NM_SETTING_CLASS(klass);
     GArray         *properties_override = _nm_sett_info_property_override_create_array();
 
-    g_type_class_add_private(klass, sizeof(NMSettingTunPrivate));
-
     object_class->get_property = _nm_setting_property_get_property_direct;
     object_class->set_property = _nm_setting_property_set_property_direct;
 
@@ -342,5 +337,5 @@ nm_setting_tun_class_init(NMSettingTunClass *klass)
                              NM_META_SETTING_TYPE_TUN,
                              NULL,
                              properties_override,
-                             NM_SETT_INFO_PRIVATE_OFFSET_FROM_CLASS);
+                             G_STRUCT_OFFSET(NMSettingTun, _priv));
 }
diff --git a/src/libnm-core-impl/nm-setting-vlan.c b/src/libnm-core-impl/nm-setting-vlan.c
index e5a99ce924..edcaf70318 100644
--- a/src/libnm-core-impl/nm-setting-vlan.c
+++ b/src/libnm-core-impl/nm-setting-vlan.c
@@ -49,20 +49,18 @@ typedef struct {
  * VLAN Settings
  */
 struct _NMSettingVlan {
-    NMSetting parent;
-    /* In the past, this struct was public API. Preserve ABI! */
+    NMSetting            parent;
+    NMSettingVlanPrivate _priv;
 };
 
 struct _NMSettingVlanClass {
     NMSettingClass parent;
-    /* In the past, this struct was public API. Preserve ABI! */
-    gpointer padding[4];
 };
 
 G_DEFINE_TYPE(NMSettingVlan, nm_setting_vlan, NM_TYPE_SETTING)
 
 #define NM_SETTING_VLAN_GET_PRIVATE(o) \
-    (G_TYPE_INSTANCE_GET_PRIVATE((o), NM_TYPE_SETTING_VLAN, NMSettingVlanPrivate))
+    _NM_GET_PRIVATE(o, NMSettingVlan, NM_IS_SETTING_VLAN, NMSetting)
 
 /*****************************************************************************/
 
@@ -848,8 +846,6 @@ nm_setting_vlan_class_init(NMSettingVlanClass *klass)
     NMSettingClass *setting_class       = NM_SETTING_CLASS(klass);
     GArray         *properties_override = _nm_sett_info_property_override_create_array();
 
-    g_type_class_add_private(klass, sizeof(NMSettingVlanPrivate));
-
     object_class->get_property = get_property;
     object_class->set_property = set_property;
     object_class->finalize     = finalize;
@@ -1039,5 +1035,5 @@ nm_setting_vlan_class_init(NMSettingVlanClass *klass)
                              NM_META_SETTING_TYPE_VLAN,
                              NULL,
                              properties_override,
-                             NM_SETT_INFO_PRIVATE_OFFSET_FROM_CLASS);
+                             G_STRUCT_OFFSET(NMSettingVlan, _priv));
 }
diff --git a/src/libnm-core-impl/nm-setting-vpn.c b/src/libnm-core-impl/nm-setting-vpn.c
index 5984f773a0..aa030626f7 100644
--- a/src/libnm-core-impl/nm-setting-vpn.c
+++ b/src/libnm-core-impl/nm-setting-vpn.c
@@ -80,20 +80,17 @@ typedef struct {
  * VPN Settings
  */
 struct _NMSettingVpn {
-    NMSetting parent;
-    /* In the past, this struct was public API. Preserve ABI! */
+    NMSetting           parent;
+    NMSettingVpnPrivate _priv;
 };
 
 struct _NMSettingVpnClass {
     NMSettingClass parent;
-    /* In the past, this struct was public API. Preserve ABI! */
-    gpointer padding[4];
 };
 
 G_DEFINE_TYPE(NMSettingVpn, nm_setting_vpn, NM_TYPE_SETTING)
 
-#define NM_SETTING_VPN_GET_PRIVATE(o) \
-    (G_TYPE_INSTANCE_GET_PRIVATE((o), NM_TYPE_SETTING_VPN, NMSettingVpnPrivate))
+#define NM_SETTING_VPN_GET_PRIVATE(o) _NM_GET_PRIVATE(o, NMSettingVpn, NM_IS_SETTING_VPN, NMSetting)
 
 /*****************************************************************************/
 
@@ -1067,8 +1064,6 @@ nm_setting_vpn_class_init(NMSettingVpnClass *klass)
     NMSettingClass *setting_class       = NM_SETTING_CLASS(klass);
     GArray         *properties_override = _nm_sett_info_property_override_create_array();
 
-    g_type_class_add_private(klass, sizeof(NMSettingVpnPrivate));
-
     object_class->get_property = get_property;
     object_class->set_property = set_property;
     object_class->finalize     = finalize;
@@ -1211,5 +1206,5 @@ nm_setting_vpn_class_init(NMSettingVpnClass *klass)
                              NM_META_SETTING_TYPE_VPN,
                              NULL,
                              properties_override,
-                             NM_SETT_INFO_PRIVATE_OFFSET_FROM_CLASS);
+                             G_STRUCT_OFFSET(NMSettingVpn, _priv));
 }
diff --git a/src/libnm-core-impl/nm-setting-vxlan.c b/src/libnm-core-impl/nm-setting-vxlan.c
index 3fb4c48d26..357a9ebd63 100644
--- a/src/libnm-core-impl/nm-setting-vxlan.c
+++ b/src/libnm-core-impl/nm-setting-vxlan.c
@@ -66,20 +66,18 @@ typedef struct {
  * VXLAN Settings
  */
 struct _NMSettingVxlan {
-    NMSetting parent;
-    /* In the past, this struct was public API. Preserve ABI! */
+    NMSetting             parent;
+    NMSettingVxlanPrivate _priv;
 };
 
 struct _NMSettingVxlanClass {
     NMSettingClass parent;
-    /* In the past, this struct was public API. Preserve ABI! */
-    gpointer padding[4];
 };
 
 G_DEFINE_TYPE(NMSettingVxlan, nm_setting_vxlan, NM_TYPE_SETTING)
 
 #define NM_SETTING_VXLAN_GET_PRIVATE(o) \
-    (G_TYPE_INSTANCE_GET_PRIVATE((o), NM_TYPE_SETTING_VXLAN, NMSettingVxlanPrivate))
+    _NM_GET_PRIVATE(o, NMSettingVxlan, NM_IS_SETTING_VXLAN, NMSetting)
 
 /*****************************************************************************/
 
@@ -428,8 +426,6 @@ nm_setting_vxlan_class_init(NMSettingVxlanClass *klass)
     NMSettingClass *setting_class       = NM_SETTING_CLASS(klass);
     GArray         *properties_override = _nm_sett_info_property_override_create_array();
 
-    g_type_class_add_private(klass, sizeof(NMSettingVxlanPrivate));
-
     object_class->get_property = _nm_setting_property_get_property_direct;
     object_class->set_property = _nm_setting_property_set_property_direct;
 
@@ -722,5 +718,5 @@ nm_setting_vxlan_class_init(NMSettingVxlanClass *klass)
                              NM_META_SETTING_TYPE_VXLAN,
                              NULL,
                              properties_override,
-                             NM_SETT_INFO_PRIVATE_OFFSET_FROM_CLASS);
+                             G_STRUCT_OFFSET(NMSettingVxlan, _priv));
 }
diff --git a/src/libnm-core-impl/nm-setting-wimax.c b/src/libnm-core-impl/nm-setting-wimax.c
index c33ad3eaa8..37483a54ec 100644
--- a/src/libnm-core-impl/nm-setting-wimax.c
+++ b/src/libnm-core-impl/nm-setting-wimax.c
@@ -41,20 +41,18 @@ typedef struct {
  * WiMax Settings
  */
 struct _NMSettingWimax {
-    NMSetting parent;
-    /* In the past, this struct was public API. Preserve ABI! */
+    NMSetting             parent;
+    NMSettingWimaxPrivate _priv;
 };
 
 struct _NMSettingWimaxClass {
     NMSettingClass parent;
-    /* In the past, this struct was public API. Preserve ABI! */
-    gpointer padding[4];
 };
 
 G_DEFINE_TYPE(NMSettingWimax, nm_setting_wimax, NM_TYPE_SETTING)
 
 #define NM_SETTING_WIMAX_GET_PRIVATE(o) \
-    (G_TYPE_INSTANCE_GET_PRIVATE((o), NM_TYPE_SETTING_WIMAX, NMSettingWimaxPrivate))
+    _NM_GET_PRIVATE(o, NMSettingWimax, NM_IS_SETTING_WIMAX, NMSetting)
 
 /*****************************************************************************/
 
@@ -157,8 +155,6 @@ nm_setting_wimax_class_init(NMSettingWimaxClass *klass)
     NMSettingClass *setting_class       = NM_SETTING_CLASS(klass);
     GArray         *properties_override = _nm_sett_info_property_override_create_array();
 
-    g_type_class_add_private(klass, sizeof(NMSettingWimaxPrivate));
-
     object_class->get_property = _nm_setting_property_get_property_direct;
     object_class->set_property = _nm_setting_property_set_property_direct;
 
@@ -206,5 +202,5 @@ nm_setting_wimax_class_init(NMSettingWimaxClass *klass)
                              NM_META_SETTING_TYPE_WIMAX,
                              NULL,
                              properties_override,
-                             NM_SETT_INFO_PRIVATE_OFFSET_FROM_CLASS);
+                             G_STRUCT_OFFSET(NMSettingWimax, _priv));
 }
diff --git a/src/libnm-core-impl/nm-setting-wired.c b/src/libnm-core-impl/nm-setting-wired.c
index 1ee16df539..31e71d6637 100644
--- a/src/libnm-core-impl/nm-setting-wired.c
+++ b/src/libnm-core-impl/nm-setting-wired.c
@@ -75,20 +75,18 @@ typedef struct {
  * Wired Ethernet Settings
  */
 struct _NMSettingWired {
-    NMSetting parent;
-    /* In the past, this struct was public API. Preserve ABI! */
+    NMSetting             parent;
+    NMSettingWiredPrivate _priv;
 };
 
 struct _NMSettingWiredClass {
     NMSettingClass parent;
-    /* In the past, this struct was public API. Preserve ABI! */
-    gpointer padding[4];
 };
 
 G_DEFINE_TYPE(NMSettingWired, nm_setting_wired, NM_TYPE_SETTING)
 
 #define NM_SETTING_WIRED_GET_PRIVATE(o) \
-    (G_TYPE_INSTANCE_GET_PRIVATE((o), NM_TYPE_SETTING_WIRED, NMSettingWiredPrivate))
+    _NM_GET_PRIVATE(o, NMSettingWired, NM_IS_SETTING_WIRED, NMSetting)
 
 /*****************************************************************************/
 
@@ -1172,8 +1170,6 @@ nm_setting_wired_class_init(NMSettingWiredClass *klass)
     NMSettingClass *setting_class       = NM_SETTING_CLASS(klass);
     GArray         *properties_override = _nm_sett_info_property_override_create_array();
 
-    g_type_class_add_private(klass, sizeof(NMSettingWiredPrivate));
-
     object_class->get_property = get_property;
     object_class->set_property = set_property;
     object_class->finalize     = finalize;
@@ -1675,5 +1671,5 @@ nm_setting_wired_class_init(NMSettingWiredClass *klass)
                              NM_META_SETTING_TYPE_WIRED,
                              NULL,
                              properties_override,
-                             NM_SETT_INFO_PRIVATE_OFFSET_FROM_CLASS);
+                             G_STRUCT_OFFSET(NMSettingWired, _priv));
 }
diff --git a/src/libnm-core-impl/nm-setting-wireless-security.c b/src/libnm-core-impl/nm-setting-wireless-security.c
index a7d12df401..cc9e4d4ef0 100644
--- a/src/libnm-core-impl/nm-setting-wireless-security.c
+++ b/src/libnm-core-impl/nm-setting-wireless-security.c
@@ -90,22 +90,18 @@ typedef struct {
  * Wi-Fi Security Settings
  */
 struct _NMSettingWirelessSecurity {
-    NMSetting parent;
-    /* In the past, this struct was public API. Preserve ABI! */
+    NMSetting                        parent;
+    NMSettingWirelessSecurityPrivate _priv;
 };
 
 struct _NMSettingWirelessSecurityClass {
     NMSettingClass parent;
-    /* In the past, this struct was public API. Preserve ABI! */
-    gpointer padding[4];
 };
 
 G_DEFINE_TYPE(NMSettingWirelessSecurity, nm_setting_wireless_security, NM_TYPE_SETTING)
 
-#define NM_SETTING_WIRELESS_SECURITY_GET_PRIVATE(o)                 \
-    (G_TYPE_INSTANCE_GET_PRIVATE((o),                               \
-                                 NM_TYPE_SETTING_WIRELESS_SECURITY, \
-                                 NMSettingWirelessSecurityPrivate))
+#define NM_SETTING_WIRELESS_SECURITY_GET_PRIVATE(o) \
+    _NM_GET_PRIVATE(o, NMSettingWirelessSecurity, NM_IS_SETTING_WIRELESS_SECURITY, NMSetting)
 
 /*****************************************************************************/
 
@@ -1389,8 +1385,6 @@ nm_setting_wireless_security_class_init(NMSettingWirelessSecurityClass *klass)
     NMSettingClass *setting_class       = NM_SETTING_CLASS(klass);
     GArray         *properties_override = _nm_sett_info_property_override_create_array();
 
-    g_type_class_add_private(klass, sizeof(NMSettingWirelessSecurityPrivate));
-
     object_class->get_property = get_property;
     object_class->set_property = set_property;
     object_class->finalize     = finalize;
@@ -1894,5 +1888,5 @@ nm_setting_wireless_security_class_init(NMSettingWirelessSecurityClass *klass)
                              NM_META_SETTING_TYPE_WIRELESS_SECURITY,
                              NULL,
                              properties_override,
-                             NM_SETT_INFO_PRIVATE_OFFSET_FROM_CLASS);
+                             G_STRUCT_OFFSET(NMSettingWirelessSecurity, _priv));
 }
diff --git a/src/libnm-core-impl/nm-setting-wireless.c b/src/libnm-core-impl/nm-setting-wireless.c
index e2cd1f4922..54bbf5e280 100644
--- a/src/libnm-core-impl/nm-setting-wireless.c
+++ b/src/libnm-core-impl/nm-setting-wireless.c
@@ -72,20 +72,18 @@ typedef struct {
  * Wi-Fi Settings
  */
 struct _NMSettingWireless {
-    NMSetting parent;
-    /* In the past, this struct was public API. Preserve ABI! */
+    NMSetting                parent;
+    NMSettingWirelessPrivate _priv;
 };
 
 struct _NMSettingWirelessClass {
     NMSettingClass parent;
-    /* In the past, this struct was public API. Preserve ABI! */
-    gpointer padding[4];
 };
 
 G_DEFINE_TYPE(NMSettingWireless, nm_setting_wireless, NM_TYPE_SETTING)
 
 #define NM_SETTING_WIRELESS_GET_PRIVATE(o) \
-    (G_TYPE_INSTANCE_GET_PRIVATE((o), NM_TYPE_SETTING_WIRELESS, NMSettingWirelessPrivate))
+    _NM_GET_PRIVATE(o, NMSettingWireless, NM_IS_SETTING_WIRELESS, NMSetting)
 
 /*****************************************************************************/
 
@@ -1309,8 +1307,6 @@ nm_setting_wireless_class_init(NMSettingWirelessClass *klass)
     NMSettingClass *setting_class       = NM_SETTING_CLASS(klass);
     GArray         *properties_override = _nm_sett_info_property_override_create_array();
 
-    g_type_class_add_private(klass, sizeof(NMSettingWirelessPrivate));
-
     object_class->set_property = set_property;
     object_class->get_property = get_property;
     object_class->finalize     = finalize;
@@ -1925,5 +1921,5 @@ nm_setting_wireless_class_init(NMSettingWirelessClass *klass)
                              NM_META_SETTING_TYPE_WIRELESS,
                              NULL,
                              properties_override,
-                             NM_SETT_INFO_PRIVATE_OFFSET_FROM_CLASS);
+                             G_STRUCT_OFFSET(NMSettingWireless, _priv));
 }
diff --git a/src/libnm-core-impl/nm-setting-wpan.c b/src/libnm-core-impl/nm-setting-wpan.c
index bc84b01e28..0bfbed7f9b 100644
--- a/src/libnm-core-impl/nm-setting-wpan.c
+++ b/src/libnm-core-impl/nm-setting-wpan.c
@@ -57,7 +57,8 @@ typedef struct {
  * Since: 1.14
  */
 struct _NMSettingWpan {
-    NMSetting parent;
+    NMSetting            parent;
+    NMSettingWpanPrivate _priv;
 };
 
 struct _NMSettingWpanClass {
@@ -67,7 +68,7 @@ struct _NMSettingWpanClass {
 G_DEFINE_TYPE(NMSettingWpan, nm_setting_wpan, NM_TYPE_SETTING)
 
 #define NM_SETTING_WPAN_GET_PRIVATE(o) \
-    (G_TYPE_INSTANCE_GET_PRIVATE((o), NM_TYPE_SETTING_WPAN, NMSettingWpanPrivate))
+    _NM_GET_PRIVATE(o, NMSettingWpan, NM_IS_SETTING_WPAN, NMSetting)
 
 /*****************************************************************************/
 
@@ -228,8 +229,6 @@ nm_setting_wpan_class_init(NMSettingWpanClass *klass)
     NMSettingClass *setting_class       = NM_SETTING_CLASS(klass);
     GArray         *properties_override = _nm_sett_info_property_override_create_array();
 
-    g_type_class_add_private(setting_class, sizeof(NMSettingWpanPrivate));
-
     object_class->get_property = _nm_setting_property_get_property_direct;
     object_class->set_property = _nm_setting_property_set_property_direct;
 
@@ -334,5 +333,5 @@ nm_setting_wpan_class_init(NMSettingWpanClass *klass)
                              NM_META_SETTING_TYPE_WPAN,
                              NULL,
                              properties_override,
-                             NM_SETT_INFO_PRIVATE_OFFSET_FROM_CLASS);
+                             G_STRUCT_OFFSET(NMSettingWpan, _priv));
 }
diff --git a/src/libnm-core-impl/nm-setting.c b/src/libnm-core-impl/nm-setting.c
index efbdc3f5da..21e1ff703d 100644
--- a/src/libnm-core-impl/nm-setting.c
+++ b/src/libnm-core-impl/nm-setting.c
@@ -58,14 +58,13 @@ typedef struct {
 
 NM_GOBJECT_PROPERTIES_DEFINE(NMSetting, PROP_NAME, );
 
-typedef struct {
+typedef struct _NMSettingPrivate {
     GenData *gendata;
 } NMSettingPrivate;
 
 G_DEFINE_ABSTRACT_TYPE(NMSetting, nm_setting, G_TYPE_OBJECT)
 
-#define NM_SETTING_GET_PRIVATE(o) \
-    (G_TYPE_INSTANCE_GET_PRIVATE((o), NM_TYPE_SETTING, NMSettingPrivate))
+#define NM_SETTING_GET_PRIVATE(o) _NM_GET_PRIVATE_PTR(o, NMSetting, NM_IS_SETTING)
 
 /*****************************************************************************/
 
@@ -429,17 +428,7 @@ has_property_type:
 
     setting_class->setting_info = &nm_meta_setting_infos[meta_type];
     sett_info->setting_class    = setting_class;
-
-    if (private_offset == NM_SETT_INFO_PRIVATE_OFFSET_FROM_CLASS) {
-        int o;
-
-        o = g_type_class_get_instance_private_offset(setting_class);
-        nm_assert(o != NM_SETT_INFO_PRIVATE_OFFSET_FROM_CLASS);
-        nm_assert(o > G_MININT16);
-        nm_assert(o < 0);
-        private_offset = o;
-    }
-    sett_info->private_offset = private_offset;
+    sett_info->private_offset   = private_offset;
 
     if (detail)
         sett_info->detail = *detail;
@@ -4374,7 +4363,13 @@ get_property(GObject *object, guint prop_id, GValue *value, GParamSpec *pspec)
 
 static void
 nm_setting_init(NMSetting *setting)
-{}
+{
+    NMSettingPrivate *priv;
+
+    priv = G_TYPE_INSTANCE_GET_PRIVATE(setting, NM_TYPE_SETTING, NMSettingPrivate);
+
+    setting->_priv = priv;
+}
 
 static void
 constructed(GObject *object)
diff --git a/src/libnm-core-impl/nm-simple-connection.c b/src/libnm-core-impl/nm-simple-connection.c
index a9c66dc72d..7d4395ff26 100644
--- a/src/libnm-core-impl/nm-simple-connection.c
+++ b/src/libnm-core-impl/nm-simple-connection.c
@@ -30,13 +30,10 @@ int         _nm_simple_connection_private_offset;
  */
 struct _NMSimpleConnection {
     GObject parent;
-    /* In the past, this struct was public API. Preserve ABI! */
 };
 
 struct _NMSimpleConnectionClass {
     GObjectClass parent;
-    /* In the past, this struct was public API. Preserve ABI! */
-    gpointer padding[4];
 };
 
 static void nm_simple_connection_interface_init(NMConnectionInterface *iface);
diff --git a/src/libnm-core-intern/nm-core-internal.h b/src/libnm-core-intern/nm-core-internal.h
index dbb5a7fa59..c5a0e8b081 100644
--- a/src/libnm-core-intern/nm-core-internal.h
+++ b/src/libnm-core-intern/nm-core-internal.h
@@ -920,8 +920,6 @@ struct _NMSettInfoSetting {
     NMSettInfoSettDetail detail;
 };
 
-#define NM_SETT_INFO_PRIVATE_OFFSET_FROM_CLASS ((gint16) G_MININT16)
-
 static inline gpointer
 _nm_setting_get_private(NMSetting *self, const NMSettInfoSetting *sett_info, guint16 offset)
 {