diff --git a/include/X11/XF86keysym.h b/include/X11/XF86keysym.h
index dd287e2493e10ec9b66feed68b973abbabcb20a4..dab122085287de7b13b617e209290482db732172 100644
--- a/include/X11/XF86keysym.h
+++ b/include/X11/XF86keysym.h
@@ -207,6 +207,8 @@
 
 #define XF86XK_RotationLockToggle 0x1008FFB7 /* Toggle screen rotation lock on/off */
 
+#define XF86XK_FullScreen	0x1008FFB8   /* Toggle fullscreen */
+
 /* Keys for special action keys (hot keys) */
 /* Virtual terminals on some operating systems */
 #define XF86XK_Switch_VT_1	0x1008FE01