diff --git a/src/core/display.c b/src/core/display.c
index c5f412ecb..228f5127e 100644
--- a/src/core/display.c
+++ b/src/core/display.c
@@ -1015,6 +1015,7 @@ meta_display_close (MetaDisplay *display,
                     guint32      timestamp)
 {
   g_assert (display != NULL);
+  g_assert (display == the_display);
 
   if (display->closing != 0)
     {