diff --git a/libnm-core/nm-setting.c b/libnm-core/nm-setting.c
index 9ce8cdb0b4..1645b4bd88 100644
--- a/libnm-core/nm-setting.c
+++ b/libnm-core/nm-setting.c
@@ -2057,6 +2057,21 @@ static void
 nm_setting_class_init (NMSettingClass *setting_class)
 {
 	GObjectClass *object_class = G_OBJECT_CLASS (setting_class);
+	GModule *self_module;
+	gpointer func;
+
+	/* loading libnm and legacy libraries libnm-util/libnm-glib at the same
+	 * time is not supported. The reason is, that both libraries use the same
+	 * glib type names ("NMSetting"), and glib does not support namespacing
+	 * to allow for that.
+	 *
+	 * Arbitrarily, add a check here, see whether a known symbol from libnm-util
+	 * is present. If it is, it indicates that the process is borked and we
+	 * abort. */
+	self_module = g_module_open (NULL, 0);
+	if (g_module_symbol (self_module, "nm_util_get_private", &func))
+		g_error ("libnm-util symbols detected; Mixing libnm with libnm-util/libnm-glib is not supported");
+	g_module_close (self_module);
 
 	g_type_class_add_private (setting_class, sizeof (NMSettingPrivate));
 
diff --git a/libnm-core/nm-utils.c b/libnm-core/nm-utils.c
index bea6b427b0..2c9c1fd0ef 100644
--- a/libnm-core/nm-utils.c
+++ b/libnm-core/nm-utils.c
@@ -236,8 +236,6 @@ static void __attribute__((constructor))
 _nm_utils_init (void)
 {
 	static int initialized = 0;
-	GModule *self;
-	gpointer func;
 
 	if (g_atomic_int_get (&initialized) != 0)
 		return;
@@ -249,11 +247,6 @@ _nm_utils_init (void)
 	 * Hence, a poor-man guard "initialized" above is more than sufficient,
 	 * although it does not guarantee that the code is not run concurrently. */
 
-	self = g_module_open (NULL, 0);
-	if (g_module_symbol (self, "nm_util_get_private", &func))
-		g_error ("libnm-util symbols detected; Mixing libnm with libnm-util/libnm-glib is not supported");
-	g_module_close (self);
-
 	bindtextdomain (GETTEXT_PACKAGE, NMLOCALEDIR);
 	bind_textdomain_codeset (GETTEXT_PACKAGE, "UTF-8");