diff --git a/src/vim.h b/src/vim.h
index bff49be..23771fb 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -2632,6 +2632,7 @@
 #define TFN_NO_DECL	0x20	// only used for GLV_NO_DECL
 #define TFN_COMPILING	0x40	// only used for GLV_COMPILING
 #define TFN_NEW_FUNC	0x80	// defining a new function
+#define TFN_ASSIGN_WITH_OP	0x100	// only for GLV_ASSIGN_WITH_OP
 
 // Values for get_lval() flags argument:
 #define GLV_QUIET	TFN_QUIET	// no error messages
@@ -2639,6 +2640,7 @@
 #define GLV_READ_ONLY	TFN_READ_ONLY	// will not change the var
 #define GLV_NO_DECL	TFN_NO_DECL	// assignment without :var or :let
 #define GLV_COMPILING	TFN_COMPILING	// variable may be defined later
+#define GLV_ASSIGN_WITH_OP TFN_ASSIGN_WITH_OP // assignment with operator
 
 #define DO_NOT_FREE_CNT 99999	// refcount for dict or list that should not
 				// be freed.