diff --git a/src/libnm-glib-aux/nm-macros-internal.h b/src/libnm-glib-aux/nm-macros-internal.h
index 71a17e3e37..0534ee5d9b 100644
--- a/src/libnm-glib-aux/nm-macros-internal.h
+++ b/src/libnm-glib-aux/nm-macros-internal.h
@@ -529,12 +529,12 @@ nm_str_realloc(char *str)
 
 /* redefine assertions to use g_assert*() */
 #undef _nm_assert_fail
-#define _nm_assert_fail(msg)                                                        \
-    G_STMT_START                                                                    \
-    {                                                                               \
-        g_assertion_message_expr(G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg); \
-        _nm_unreachable_code();                                                     \
-    }                                                                               \
+#define _nm_assert_fail(msg)                                                              \
+    G_STMT_START                                                                          \
+    {                                                                                     \
+        g_assertion_message_expr(G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, "" msg ""); \
+        _nm_unreachable_code();                                                           \
+    }                                                                                     \
     G_STMT_END
 
 #undef _NM_ASSERT_FAIL_ENABLED
diff --git a/src/libnm-std-aux/nm-std-aux.h b/src/libnm-std-aux/nm-std-aux.h
index 75703e70b4..a5e5abd3d5 100644
--- a/src/libnm-std-aux/nm-std-aux.h
+++ b/src/libnm-std-aux/nm-std-aux.h
@@ -221,15 +221,14 @@ typedef uint64_t _nm_bitwise nm_be64_t;
 
 #ifndef NDEBUG
 #define _NM_ASSERT_FAIL_ENABLED 1
-#define _nm_assert_fail(msg)    __assert_fail((msg), __FILE__, __LINE__, __func__)
+#define _nm_assert_fail(msg)                                     \
+    __assert_fail(((NM_MORE_ASSERTS) ? "" msg "" : "<dropped>"), \
+                  __FILE__,                                      \
+                  __LINE__,                                      \
+                  ((NM_MORE_ASSERTS) ? __func__ : "<unknown-fcn>"))
 #else
 #define _NM_ASSERT_FAIL_ENABLED 0
-#define _nm_assert_fail(msg)                 \
-    do {                                     \
-        _nm_unused const char *_msg = (msg); \
-                                             \
-        _nm_unreachable_code();              \
-    } while (0)
+#define _nm_assert_fail(msg)    ((void) ("" msg ""), _nm_unreachable_code())
 #endif
 
 #define NM_MORE_ASSERTS_EFFECTIVE (_NM_ASSERT_FAIL_ENABLED ? NM_MORE_ASSERTS : 0)