diff --git a/lib/broadway_cloud_pub_sub/pull_client.ex b/lib/broadway_cloud_pub_sub/pull_client.ex
index b22ed89..20e379d 100644
--- a/lib/broadway_cloud_pub_sub/pull_client.ex
+++ b/lib/broadway_cloud_pub_sub/pull_client.ex
@@ -172,7 +172,7 @@ defmodule BroadwayCloudPubSub.PullClient do
   end
 
   defp decode_message(%{"data" => nil} = message), do: message
-  defp decode_message(message) when is_map(message) and not is_map_key(message, "data"), do: message
+  defp decode_message(%{} = message) when not is_map_key(message, "data"), do: message
 
   defp headers(config) do
     token = get_token(config)