diff --git a/lib/oauth2/client.ex b/lib/oauth2/client.ex
index c3bbf13..3f15055 100644
--- a/lib/oauth2/client.ex
+++ b/lib/oauth2/client.ex
@@ -244,8 +244,21 @@ defmodule OAuth2.Client do
   @spec get_token!(t, params, headers, Keyword.t) :: Client.t | Error.t
   def get_token!(client, params \\ [], headers \\ [], opts \\ []) do
     case get_token(client, params, headers, opts) do
-      {:ok, client} -> client
-      {:error, error} -> raise error
+      {:ok, client} ->
+        client
+      {:error, %Response{status_code: code, headers: headers, body: body}} ->
+        raise %Error{reason: """
+        Server responded with status: #{code}
+
+        Headers:
+
+        #{Enum.reduce(headers, "", fn {k, v}, acc -> acc <> "#{k}: #{v}\n" end)}
+        Body:
+
+        #{inspect body}
+        """}
+      {:error, error} ->
+        raise error
     end
   end
 
diff --git a/test/oauth2/client_test.exs b/test/oauth2/client_test.exs
index 75f682a..182173f 100644
--- a/test/oauth2/client_test.exs
+++ b/test/oauth2/client_test.exs
@@ -7,6 +7,7 @@ defmodule OAuth2.ClientTest do
   import OAuth2.TestHelpers
 
   alias OAuth2.Client
+  alias OAuth2.Response
 
   setup do
     server = Bypass.open
@@ -59,6 +60,24 @@ defmodule OAuth2.ClientTest do
     assert token.access_token == "test1234"
   end
 
+  test "get_token, get_token! when response error", %{client: client, server: server} do
+    code = [code: "code1234"]
+    headers = [{"accept", "application/json"}]
+
+    bypass server, "POST", "/oauth/token", fn conn ->
+      assert conn.query_string == ""
+      send_resp(conn, 500, ~s({"error":"missing_client_id"}))
+    end
+
+    assert {:error, error} = Client.get_token(client, code, headers)
+    assert %Response{body: body, status_code: 500} = error
+    assert body == %{"error" => "missing_client_id"}
+
+    assert_raise OAuth2.Error, ~r/Body/, fn ->
+      Client.get_token!(client, code, headers)
+    end
+  end
+
   test "refresh_token and refresh_token! with a POST", %{server: server, client_with_token: client} do
     bypass server, "POST", "/oauth/token", fn conn ->
       assert get_req_header(conn, "authorization") == []
@@ -124,6 +143,14 @@ defmodule OAuth2.ClientTest do
     assert {"content-type", "application/xml"} = List.keyfind(client.headers, "content-type", 0)
   end
 
+  test "basic_auth", %{client: client} do
+    %OAuth2.Client{client_id: id, client_secret: secret} = client
+    client = basic_auth(client)
+
+    assert {"authorization", value} = List.keyfind(client.headers, "authorization", 0)
+    assert value == "Basic " <> Base.encode64(id <> ":" <> secret)
+  end
+
   ## GET
 
   test "GET", %{server: server, client_with_token: client} do