diff --git a/ruby/ext/google/protobuf_c/map.c b/ruby/ext/google/protobuf_c/map.c
index d1a648dae..2f6de4d8b 100644
--- a/ruby/ext/google/protobuf_c/map.c
+++ b/ruby/ext/google/protobuf_c/map.c
@@ -682,6 +682,8 @@ void Map_register(VALUE module) {
   rb_define_method(klass, "length", Map_length, 0);
   rb_define_method(klass, "size", Map_length, 0);
   rb_define_method(klass, "dup", Map_dup, 0);
+  // Also define #clone so that we don't inherit Object#clone.
+  rb_define_method(klass, "clone", Map_dup, 0);
   rb_define_method(klass, "==", Map_eq, 1);
   rb_define_method(klass, "freeze", Map_freeze, 0);
   rb_define_method(klass, "hash", Map_hash, 0);