diff --git a/src/vim.h b/src/vim.h
index 6c846c1..5b74203 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -1842,7 +1842,8 @@
 #define VV_OP		52
 #define VV_SEARCHFORWARD 53
 #define VV_OLDFILES	54
-#define VV_LEN		55	/* number of v: vars */
+#define VV_WINDOWID	55
+#define VV_LEN		56	/* number of v: vars */
 
 #ifdef FEAT_CLIPBOARD