diff --git a/config.h b/config.h
index 656f7b5..203562c 100644
--- a/config.h
+++ b/config.h
@@ -1,5 +1,7 @@
 /* See LICENSE file for copyright and license details. */
 
+#include <X11/XF86keysym.h>
+
 /* appearance */
 static const unsigned int borderpx  = 3;        /* border pixel of windows */
 static const unsigned int snap      = 32;       /* snap pixel */