diff --git a/src/tests/test-client.c b/src/tests/test-client.c
index a468e6137..6ee7b6c4a 100644
--- a/src/tests/test-client.c
+++ b/src/tests/test-client.c
@@ -1003,6 +1003,8 @@ main(int argc, char **argv)
   gtk_init (NULL, NULL);
 
   screen = gdk_screen_get_default ();
+  g_assert_true (gdk_screen_is_composited (screen));
+
   provider = gtk_css_provider_new ();
   static const char *no_decoration_css =
     "decoration {"