diff --git a/src/vim9execute.c b/src/vim9execute.c
index f20ff40..de49aaa 100644
--- a/src/vim9execute.c
+++ b/src/vim9execute.c
@@ -3184,7 +3184,7 @@
     copy_tv(tv, &mtv);
 
     // 'name' can either be a object variable or a object method
-    int		namelen = STRLEN(iptr->isn_arg.string);
+    int		namelen = (int)STRLEN(iptr->isn_arg.string);
     int		save_did_emsg = did_emsg;
 
     if (get_member_tv(obj->obj_class, TRUE, iptr->isn_arg.string, namelen,