diff --git a/src/vim9execute.c b/src/vim9execute.c
index f15b93d..9b7f87b 100644
--- a/src/vim9execute.c
+++ b/src/vim9execute.c
@@ -963,9 +963,12 @@
 store_var(char_u *name, typval_T *tv)
 {
     funccal_entry_T entry;
+    int		    flags = ASSIGN_DECL;
 
+    if (tv->v_lock)
+	flags |= ASSIGN_CONST;
     save_funccal(&entry);
-    set_var_const(name, NULL, tv, FALSE, ASSIGN_DECL, 0);
+    set_var_const(name, NULL, tv, FALSE, flags, 0);
     restore_funccal();
 }