diff --git a/hoauth2.cabal b/hoauth2.cabal
--- a/hoauth2.cabal
+++ b/hoauth2.cabal
@@ -1,6 +1,6 @@
 Name:                hoauth2
 -- (http://www.haskell.org/haskellwiki/Package_versioning_policy)
-Version:             0.2.5
+Version:             0.2.5.1
 
 Synopsis:            hoauth2
 Description:         
diff --git a/src/Network/OAuth2/HTTP/HttpClient.hs b/src/Network/OAuth2/HTTP/HttpClient.hs
--- a/src/Network/OAuth2/HTTP/HttpClient.hs
+++ b/src/Network/OAuth2/HTTP/HttpClient.hs
@@ -63,8 +63,8 @@
 -- | Conduct GET request.
 --
 doSimpleGetRequest :: URI                           -- ^ URL
-                      -> IO (Response BSL.ByteString)  -- ^ Response as ByteString
-doSimpleGetRequest url = doGetRequest (bsToS url) []
+                      -> IO BSL.ByteString  -- ^ Response as ByteString
+doSimpleGetRequest url = doGetRequest (bsToS url) [] >>= handleResponse
 
 -- | Conduct GET request and return response as JSON.
 --
diff --git a/src/Network/OAuth2/OAuth2.hs b/src/Network/OAuth2/OAuth2.hs
--- a/src/Network/OAuth2/OAuth2.hs
+++ b/src/Network/OAuth2/OAuth2.hs
@@ -27,6 +27,7 @@
                      , oauthAccessTokenEndpoint :: BS.ByteString
                      , oauthCallback            :: Maybe BS.ByteString
                      , oauthAccessToken         :: Maybe BS.ByteString
+                       -- ^ TODO: why not Maybe AccessToken???
                      } deriving (Show, Eq)
 
 -- | Simple Exception representation.
@@ -121,9 +122,13 @@
 -- UTILs
 --------------------------------------------------
 
--- | Append query parameters
+-- | Append query parameters with '?'
 appendQueryParam :: URI -> QueryParams -> URI
 appendQueryParam uri q = uri `BS.append` renderSimpleQuery True q
+
+-- | Append query parameters with '&'.
+appendQueryParam' :: URI -> QueryParams -> URI
+appendQueryParam' uri q = uri `BS.append` "&" `BS.append` renderSimpleQuery False q
 
 
 -- | For GET method API.