diff --git "a/C:\\Users\\LAZARI~1\\AppData\\Local\\Temp\\vm_8193.c" "b/P:\\ri\\sandbox\\rb193\\vm_method.c"
index a28bd8e..738f5ec 100644
--- "a/C:\\Users\\LAZARI~1\\AppData\\Local\\Temp\\vm_8193.c"
+++ "b/P:\\ri\\sandbox\\rb193\\vm_method.c"
@@ -261,6 +261,7 @@ method_added(VALUE klass, ID mid)
 rb_method_entry_t *
 rb_add_method(VALUE klass, ID mid, rb_method_type_t type, void *opts, rb_method_flag_t noex)
 {
+    int callback = TRUE; /* see #5015 */
     rb_thread_t *th;
     rb_control_frame_t *cfp;
     int line;
@@ -299,12 +300,16 @@ rb_add_method(VALUE klass, ID mid, rb_method_type_t type, void *opts, rb_method_
 	def->body.optimize_type = (enum method_optimized_type)opts;
 	break;
       case VM_METHOD_TYPE_ZSUPER:
+	break;
       case VM_METHOD_TYPE_UNDEF:
+	callback = FALSE;
 	break;
       default:
 	rb_bug("rb_add_method: unsupported method type (%d)\n", type);
     }
-    method_added(klass, mid);
+    if (callback) {
+	method_added(klass, mid);
+    }
     return me;
 }