diff --git a/lib/slipstream/serializer/phoenix_socket_v2_serializer.ex b/lib/slipstream/serializer/phoenix_socket_v2_serializer.ex
index a18ac99..23d2a8c 100644
--- a/lib/slipstream/serializer/phoenix_socket_v2_serializer.ex
+++ b/lib/slipstream/serializer/phoenix_socket_v2_serializer.ex
@@ -103,9 +103,11 @@ defmodule Slipstream.Serializer.PhoenixSocketV2Serializer do
   defp decode_binary!(<<
          @push::size(8),
          join_ref_size::size(8),
+         ref_size::size(8),
          topic_size::size(8),
          event_size::size(8),
          join_ref::binary-size(join_ref_size),
+         ref::binary-size(ref_size),
          topic::binary-size(topic_size),
          event::binary-size(event_size),
          data::binary
@@ -114,7 +116,7 @@ defmodule Slipstream.Serializer.PhoenixSocketV2Serializer do
       topic: topic,
       event: event,
       payload: {:binary, data},
-      ref: nil,
+      ref: ref,
       join_ref: join_ref
     }
   end
diff --git a/test/slipstream/serializer/phoenix_socket_v2_serializer_test.exs b/test/slipstream/serializer/phoenix_socket_v2_serializer_test.exs
index e569756..2cc6a9e 100644
--- a/test/slipstream/serializer/phoenix_socket_v2_serializer_test.exs
+++ b/test/slipstream/serializer/phoenix_socket_v2_serializer_test.exs
@@ -38,4 +38,36 @@ defmodule Slipstream.Serializer.PhoenixSocketV2SerializerTest do
       end)
     end
   end
+
+  describe "encode!/2 and decode!/2 round-trip" do
+    test "binary payload messages encode and decode correctly" do
+      original_message = %Message{
+        topic: "test:topic",
+        event: "test_event",
+        payload: {:binary, <<1, 2, 3, 4>>},
+        ref: "123",
+        join_ref: "456"
+      }
+
+      encoded = encode!(original_message, json_parser: Jason)
+      decoded = decode!(encoded, opcode: :binary, json_parser: Jason)
+
+      assert decoded == original_message
+    end
+
+    test "text/JSON payload messages encode and decode correctly" do
+      original_message = %Message{
+        topic: "test:topic",
+        event: "test_event",
+        payload: %{"foo" => "bar", "baz" => 123},
+        ref: "123",
+        join_ref: "456"
+      }
+
+      encoded = encode!(original_message, json_parser: Jason)
+      decoded = decode!(encoded, opcode: :text, json_parser: Jason)
+
+      assert decoded == original_message
+    end
+  end
 end