diff --git a/nls/blackbox-nls.hh b/nls/blackbox-nls.hh
index 4a17d81b..6390e6a0 100644
--- a/nls/blackbox-nls.hh
+++ b/nls/blackbox-nls.hh
@@ -114,6 +114,7 @@
 #define WindowmenuStick 0x8
 #define WindowmenuKillClient 0x9
 #define WindowmenuClose 0xa
+#define WindowmenuTab 0xb
 
 #define WorkspaceSet 0xb
 #define WorkspaceDefaultNameFormat 0x1