diff --git a/configure.ac b/configure.ac
index ee6bd9af79..01a1dacf43 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1157,7 +1157,12 @@ fi
 
 NM_COMPILER_WARNINGS(AM_CFLAGS, ${more_warnings_default})
 
-NM_COMPILER_WARNING_FLAG(LIBSYSTEMD_NM_CFLAGS, "-Wno-gnu-variable-sized-type-not-at-end")
+for w in \
+    -Wno-nonnull-compare \
+    -Wno-calloc-transposed-args \
+    ; do
+    NM_COMPILER_WARNING_FLAG(LIBSYSTEMD_NM_CFLAGS, "$w")
+done
 AC_SUBST(LIBSYSTEMD_NM_CFLAGS)
 
 CC_CHECK_FLAGS_APPEND([with_cflags], [CFLAGS], [\
diff --git a/src/core/nm-audit-manager.c b/src/core/nm-audit-manager.c
index 4e134d1a3c..7cf5294603 100644
--- a/src/core/nm-audit-manager.c
+++ b/src/core/nm-audit-manager.c
@@ -185,13 +185,16 @@ nm_audit_log(NMAuditManager *self,
     priv = NM_AUDIT_MANAGER_GET_PRIVATE(self);
 
     if (priv->auditd_fd >= 0) {
-        audit_log_user_message(priv->auditd_fd,
-                               AUDIT_USYS_CONFIG,
-                               build_message(&strbuf, BACKEND_AUDITD, fields),
-                               NULL,
-                               NULL,
-                               NULL,
-                               success);
+        int r;
+
+        r = audit_log_user_message(priv->auditd_fd,
+                                   AUDIT_USYS_CONFIG,
+                                   build_message(&strbuf, BACKEND_AUDITD, fields),
+                                   NULL,
+                                   NULL,
+                                   NULL,
+                                   success);
+        (void) r;
     }
 #endif
 
diff --git a/src/core/tests/config/test-config.c b/src/core/tests/config/test-config.c
index 054b9003f4..2b27d53549 100644
--- a/src/core/tests/config/test-config.c
+++ b/src/core/tests/config/test-config.c
@@ -1076,7 +1076,7 @@ _set_values_intern_atomic_section_2_set(NMConfig            *config,
     g_key_file_set_value(keyfile,
                          NM_CONFIG_KEYFILE_GROUPPREFIX_INTERN "with-whitespace",
                          "key2",
-                         " b c\\,  d  ");
+                         " b c\\\\,  d  ");
     *out_expected_changes = NM_CONFIG_CHANGE_CAUSE_SET_VALUES | NM_CONFIG_CHANGE_VALUES
                             | NM_CONFIG_CHANGE_VALUES_INTERN;
 }
diff --git a/src/libnm-lldp/nm-lldp-neighbor.c b/src/libnm-lldp/nm-lldp-neighbor.c
index a2a9695e85..0379cf3844 100644
--- a/src/libnm-lldp/nm-lldp-neighbor.c
+++ b/src/libnm-lldp/nm-lldp-neighbor.c
@@ -648,9 +648,10 @@ nm_lldp_neighbor_tlv_get_oui(NMLldpNeighbor *n, uint8_t oui[static 3], uint8_t *
     int            r;
 
     g_return_val_if_fail(n, -EINVAL);
-    g_return_val_if_fail(oui, -EINVAL);
     g_return_val_if_fail(subtype, -EINVAL);
 
+    nm_assert(oui);
+
     r = nm_lldp_neighbor_tlv_is_type(n, NM_LLDP_TYPE_PRIVATE);
     if (r < 0)
         return r;
diff --git a/src/libnm-systemd-core/meson.build b/src/libnm-systemd-core/meson.build
index 6175e42c4d..7e700e6464 100644
--- a/src/libnm-systemd-core/meson.build
+++ b/src/libnm-systemd-core/meson.build
@@ -28,6 +28,7 @@ libnm_systemd_core = static_library(
     top_inc,
     src_inc,
   ],
+  c_args: libnm_systemd_common_cflags,
   dependencies: [
     libnm_systemd_shared_dep_inc,
     glib_dep,
diff --git a/src/libnm-systemd-shared/meson.build b/src/libnm-systemd-shared/meson.build
index b32bd7f6e0..3e5d1db859 100644
--- a/src/libnm-systemd-shared/meson.build
+++ b/src/libnm-systemd-shared/meson.build
@@ -58,6 +58,7 @@ libnm_systemd_shared = static_library(
     top_inc,
     src_inc,
   ],
+  c_args: libnm_systemd_common_cflags,
   dependencies: glib_dep,
 )
 
diff --git a/src/meson.build b/src/meson.build
index 92e95e68ef..5d85dafc21 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -69,6 +69,15 @@ libn_dhcp4 = static_library(
 
 ###############################################################################
 
+libnm_systemd_common_cflags = [ ]
+
+libnm_systemd_common_cflags += cc.get_supported_arguments([
+  '-Wno-nonnull-compare',
+  '-Wno-calloc-transposed-args',
+])
+
+###############################################################################
+
 subdir('libnm-std-aux')
 subdir('libnm-glib-aux')
 subdir('libnm-log-null')