diff --git a/gio/tests/appmonitor.c b/gio/tests/appmonitor.c
index 4ea9b7cb8..425a600f6 100644
--- a/gio/tests/appmonitor.c
+++ b/gio/tests/appmonitor.c
@@ -104,6 +104,7 @@ main (int argc, char *argv[])
   gchar *path;
 
   path = g_mkdtemp (g_strdup ("app_monitor_XXXXXX"));
+  g_setenv ("XDG_DATA_DIRS", path, TRUE);
   g_setenv ("XDG_DATA_HOME", path, TRUE);
 
   g_test_init (&argc, &argv, NULL);