1 files changed, 5 insertions, 0 deletions
diff --git a/vm_method.c b/vm_method.c
index f1235dcd47..3811f48246 100644
--- a/vm_method.c
+++ b/vm_method.c
@@ -985,6 +985,11 @@ set_method_visibility(VALUE self, int argc, VALUE *argv, rb_method_flag_t ex)
 {
     int i;
     secure_visibility(self);
+
+    if (argc == 0) {
+	rb_warning("%s with no argument is just ignored", rb_id2name(rb_frame_callee()));
+    }
+
     for (i = 0; i < argc; i++) {
 	VALUE v = argv[i];
 	ID id = rb_check_id(&v);