diff --git a/clients/common/nm-secret-agent-simple.c b/clients/common/nm-secret-agent-simple.c
index f89d225902..e2502768d7 100644
--- a/clients/common/nm-secret-agent-simple.c
+++ b/clients/common/nm-secret-agent-simple.c
@@ -70,9 +70,18 @@ typedef struct {
 	gboolean enabled;
 } NMSecretAgentSimplePrivate;
 
+struct _NMSecretAgentSimple {
+	NMSecretAgentOld parent;
+	NMSecretAgentSimplePrivate _priv;
+};
+
+struct _NMSecretAgentSimpleClass {
+	NMSecretAgentOldClass parent;
+};
+
 G_DEFINE_TYPE (NMSecretAgentSimple, nm_secret_agent_simple, NM_TYPE_SECRET_AGENT_OLD)
 
-#define NM_SECRET_AGENT_SIMPLE_GET_PRIVATE(o) (G_TYPE_INSTANCE_GET_PRIVATE ((o), NM_TYPE_SECRET_AGENT_SIMPLE, NMSecretAgentSimplePrivate))
+#define NM_SECRET_AGENT_SIMPLE_GET_PRIVATE(self)  _NM_GET_PRIVATE (self, NMSecretAgentSimple, NM_IS_SECRET_AGENT_SIMPLE, NMSecretAgentOld)
 
 /*****************************************************************************/
 
@@ -1160,8 +1169,6 @@ nm_secret_agent_simple_class_init (NMSecretAgentSimpleClass *klass)
 	GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
 	NMSecretAgentOldClass *agent_class = NM_SECRET_AGENT_OLD_CLASS (klass);
 
-	g_type_class_add_private (klass, sizeof (NMSecretAgentSimplePrivate));
-
 	gobject_class->finalize = nm_secret_agent_simple_finalize;
 
 	agent_class->get_secrets = nm_secret_agent_simple_get_secrets;
diff --git a/clients/common/nm-secret-agent-simple.h b/clients/common/nm-secret-agent-simple.h
index 0ad57a0531..89e4cf3ccf 100644
--- a/clients/common/nm-secret-agent-simple.h
+++ b/clients/common/nm-secret-agent-simple.h
@@ -51,13 +51,8 @@ typedef struct {
 
 #define NM_SECRET_AGENT_SIMPLE_REQUEST_SECRETS  "request-secrets"
 
-typedef struct {
-	NMSecretAgentOld parent;
-} NMSecretAgentSimple;
-
-typedef struct {
-	NMSecretAgentOldClass parent;
-} NMSecretAgentSimpleClass;
+typedef struct _NMSecretAgentSimple      NMSecretAgentSimple;
+typedef struct _NMSecretAgentSimpleClass NMSecretAgentSimpleClass;
 
 GType nm_secret_agent_simple_get_type (void);