diff --git a/src/tests/monitor-unit-tests.c b/src/tests/monitor-unit-tests.c
index 2340438d0..ad0cdda62 100644
--- a/src/tests/monitor-unit-tests.c
+++ b/src/tests/monitor-unit-tests.c
@@ -343,6 +343,8 @@ create_monitor_test_clients (void)
 {
   GError *error = NULL;
 
+  test_wait_for_x11_display ();
+
   meta_x11_display_set_alarm_filter (meta_get_display ()->x11_display,
                                      monitor_tests_alarm_filter, NULL);
 
diff --git a/src/tests/test-runner.c b/src/tests/test-runner.c
index 7560c957e..950556233 100644
--- a/src/tests/test-runner.c
+++ b/src/tests/test-runner.c
@@ -66,6 +66,8 @@ test_case_new (void)
 {
   TestCase *test = g_new0 (TestCase, 1);
 
+  test_wait_for_x11_display ();
+
   meta_x11_display_set_alarm_filter (meta_get_display ()->x11_display,
                                      test_case_alarm_filter, test);
 
diff --git a/src/tests/test-utils.c b/src/tests/test-utils.c
index bc4b97f92..cfade80c5 100644
--- a/src/tests/test-utils.c
+++ b/src/tests/test-utils.c
@@ -533,3 +533,17 @@ test_get_plugin_name (void)
   else
     return "libdefault";
 }
+
+void
+test_wait_for_x11_display (void)
+{
+  MetaDisplay *display;
+
+  display = meta_get_display ();
+  g_assert_nonnull (display);
+
+  while (!display->x11_display)
+    g_main_context_iteration (NULL, TRUE);
+
+  g_assert_nonnull (display->x11_display);
+}
diff --git a/src/tests/test-utils.h b/src/tests/test-utils.h
index 2f1a73116..1710b98e0 100644
--- a/src/tests/test-utils.h
+++ b/src/tests/test-utils.h
@@ -84,4 +84,6 @@ void test_client_destroy (TestClient *client);
 
 const char * test_get_plugin_name (void);
 
+void test_wait_for_x11_display (void);
+
 #endif /* TEST_UTILS_H */