diff --git a/src/vim.h b/src/vim.h
index 0a0b2f8..2bafda4 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -2776,6 +2776,7 @@
 #define GLV_COMPILING	TFN_COMPILING	// variable may be defined later
 #define GLV_ASSIGN_WITH_OP TFN_ASSIGN_WITH_OP // assignment with operator
 #define GLV_PREFER_FUNC	0x10000		// prefer function above variable
+#define GLV_FOR_LOOP	0x20000		// assigning to a loop variable
 
 #define DO_NOT_FREE_CNT 99999	// refcount for dict or list that should not
 				// be freed.