diff --git a/lib/phoenix/test/conn_test.ex b/lib/phoenix/test/conn_test.ex
index d7a08b2456..ffd002a580 100644
--- a/lib/phoenix/test/conn_test.ex
+++ b/lib/phoenix/test/conn_test.ex
@@ -370,7 +370,7 @@ defmodule Phoenix.ConnTest do
     if given == status do
       body
     else
-      raise "expected response with status #{given}, got: #{status}, with body:\n#{body}"
+      raise "expected response with status #{given}, got: #{status}, with body:\n#{inspect(body)}"
     end
   end
 
diff --git a/test/phoenix/test/conn_test.exs b/test/phoenix/test/conn_test.exs
index d256db7480..2269aaee0e 100644
--- a/test/phoenix/test/conn_test.exs
+++ b/test/phoenix/test/conn_test.exs
@@ -264,9 +264,14 @@ defmodule Phoenix.Test.ConnTest do
     end
 
     assert_raise RuntimeError,
-                 "expected response with status 200, got: 404, with body:\noops", fn ->
+                 "expected response with status 200, got: 404, with body:\n\"oops\"", fn ->
       build_conn(:get, "/") |> resp(404, "oops") |> response(200)
     end
+
+    assert_raise RuntimeError,
+                 "expected response with status 200, got: 404, with body:\n<<192>>", fn ->
+      build_conn(:get, "/") |> resp(404, <<192>>) |> response(200)
+    end
   end
 
   test "html_response/2" do
@@ -313,7 +318,7 @@ defmodule Phoenix.Test.ConnTest do
       |> json_response(200)
     end
 
-    assert_raise RuntimeError, ~s(expected response with status 200, got: 400, with body:\n{"error": "oh oh"}), fn ->
+    assert_raise RuntimeError, ~s(expected response with status 200, got: 400, with body:\n) <> inspect(~s({"error": "oh oh"})), fn ->
       build_conn(:get, "/")
       |> put_resp_content_type("application/json")
       |> resp(400, ~s({"error": "oh oh"}))