diff --git a/kutils/kidletime/xsyncbasedpoller.h b/kutils/kidletime/xsyncbasedpoller.h
index b108a55a..7e6c9d06 100644
--- a/kutils/kidletime/xsyncbasedpoller.h
+++ b/kutils/kidletime/xsyncbasedpoller.h
@@ -28,6 +28,7 @@
 
 #include <X11/Xlib.h>
 #include <X11/extensions/sync.h>
+#include <fixx11h.h>
 
 class XSyncBasedPoller : public AbstractSystemPoller
 {