diff --git a/src/vim.h b/src/vim.h
index 1dedd81..f19a4fe 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -1232,6 +1232,7 @@
 #define SID_ENV		-4	// for sourcing environment variable
 #define SID_ERROR	-5	// option was reset because of an error
 #define SID_NONE	-6	// don't set scriptID
+#define SID_WINLAYOUT	-7	// changing window size
 
 /*
  * Events for autocommands.