diff --git a/include/msgpack/v1/object.hpp b/include/msgpack/v1/object.hpp
index c5dfbe1f..23f1ab1f 100644
--- a/include/msgpack/v1/object.hpp
+++ b/include/msgpack/v1/object.hpp
@@ -370,7 +370,7 @@ struct object_pack_visitor {
         return true;
     }
     bool start_map(uint32_t num_kv_pairs) {
-        m_packer.pack_array(num_kv_pairs);
+        m_packer.pack_map(num_kv_pairs);
         return true;
     }
     bool start_map_key() {