diff --git a/src/eggsmclient-private.h b/src/eggsmclient-private.h
index dc07ea4..6c7d100 100644
--- a/src/eggsmclient-private.h
+++ b/src/eggsmclient-private.h
@@ -20,6 +20,7 @@
 #ifndef __EGG_SM_CLIENT_PRIVATE_H__
 #define __EGG_SM_CLIENT_PRIVATE_H__
 
+#include <gtk/gtk.h>
 #if !GTK_CHECK_VERSION (3, 0, 0)
 #include <gdkconfig.h>
 #endif