diff --git a/http_fetcher_unittest.cc b/http_fetcher_unittest.cc
index a579ea3..0a38c5c 100644
--- a/http_fetcher_unittest.cc
+++ b/http_fetcher_unittest.cc
@@ -339,6 +339,7 @@
     data.append(bytes, length);
   }
   virtual void TransferComplete(HttpFetcher* fetcher, bool successful) {
+    EXPECT_TRUE(successful);
     g_main_loop_quit(loop_);
   }
   string data;