diff --git a/object.c b/object.c
index 7a9ee001e6..fc8416fdb7 100644
--- a/object.c
+++ b/object.c
@@ -536,6 +536,9 @@ rb_obj_dup(VALUE obj)
     init_copy(dup, obj);
     rb_funcall(dup, id_init_dup, 1, obj);
 
+    if (rb_block_given_p()) {
+        rb_yield(dup);
+    }
     return dup;
 }