diff --git a/shared/nm-glib-aux/nm-shared-utils.c b/shared/nm-glib-aux/nm-shared-utils.c
index 9ed8e7ca34..3bc96bcf98 100644
--- a/shared/nm-glib-aux/nm-shared-utils.c
+++ b/shared/nm-glib-aux/nm-shared-utils.c
@@ -3885,7 +3885,7 @@ nm_utils_g_slist_strlist_join (const GSList *a, const char *separator)
 
 /*****************************************************************************/
 
-gpointer
+NMUtilsUserData *
 _nm_utils_user_data_pack (int nargs, gconstpointer *args)
 {
 	int i;
@@ -3897,13 +3897,13 @@ _nm_utils_user_data_pack (int nargs, gconstpointer *args)
 	data = g_slice_alloc (((gsize) nargs) * sizeof (gconstpointer));
 	for (i = 0; i < nargs; i++)
 		data[i] = (gpointer) args[i];
-	return data;
+	return (NMUtilsUserData *) data;
 }
 
 void
-_nm_utils_user_data_unpack (gpointer user_data, int nargs, ...)
+_nm_utils_user_data_unpack (NMUtilsUserData *user_data, int nargs, ...)
 {
-	gpointer *data = user_data;
+	gpointer *data = (gpointer *) user_data;
 	va_list ap;
 	int i;
 
diff --git a/shared/nm-glib-aux/nm-shared-utils.h b/shared/nm-glib-aux/nm-shared-utils.h
index d1347c63bf..ed9a0b9862 100644
--- a/shared/nm-glib-aux/nm-shared-utils.h
+++ b/shared/nm-glib-aux/nm-shared-utils.h
@@ -1746,12 +1746,14 @@ nm_utils_process_state_is_dead (char pstate)
 
 /*****************************************************************************/
 
-gpointer _nm_utils_user_data_pack (int nargs, gconstpointer *args);
+typedef struct _NMUtilsUserData NMUtilsUserData;
+
+NMUtilsUserData *_nm_utils_user_data_pack (int nargs, gconstpointer *args);
 
 #define nm_utils_user_data_pack(...) \
 	_nm_utils_user_data_pack(NM_NARG (__VA_ARGS__), (gconstpointer[]) { __VA_ARGS__ })
 
-void _nm_utils_user_data_unpack (gpointer user_data, int nargs, ...);
+void _nm_utils_user_data_unpack (NMUtilsUserData *user_data, int nargs, ...);
 
 #define nm_utils_user_data_unpack(user_data, ...) \
 	_nm_utils_user_data_unpack(user_data, NM_NARG (__VA_ARGS__), __VA_ARGS__)