diff --git a/example/Keys.hs b/example/Keys.hs
--- a/example/Keys.hs
+++ b/example/Keys.hs
@@ -1,75 +1,69 @@
 {-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE QuasiQuotes #-}
+{-# LANGUAGE QuasiQuotes       #-}
 
 module Keys where
 
-import Data.ByteString (ByteString)
-import Network.OAuth.OAuth2
-import URI.ByteString.QQ
+import           Data.ByteString                ( ByteString )
+import           Network.OAuth.OAuth2
+import           URI.ByteString.QQ
 
 weiboKey :: OAuth2
-weiboKey =
-  OAuth2
-    { oauthClientId = "xxxxxxxxxxxxxxx",
-      oauthClientSecret = Just "xxxxxxxxxxxxxxxxxxxxxx",
-      oauthCallback = Just [uri|http://127.0.0.1:9988/oauthCallback|],
-      oauthOAuthorizeEndpoint = [uri|https://api.weibo.com/oauth2/authorize|],
-      oauthAccessTokenEndpoint = [uri|https://api.weibo.com/oauth2/access_token|]
-    }
+weiboKey = OAuth2
+  { oauthClientId            = "xxxxxxxxxxxxxxx"
+  , oauthClientSecret        = Just "xxxxxxxxxxxxxxxxxxxxxx"
+  , oauthCallback            = Just [uri|http://127.0.0.1:9988/oauthCallback|]
+  , oauthOAuthorizeEndpoint  = [uri|https://api.weibo.com/oauth2/authorize|]
+  , oauthAccessTokenEndpoint = [uri|https://api.weibo.com/oauth2/access_token|]
+  }
 
 -- | http://developer.github.com/v3/oauth/
 githubKey :: OAuth2
-githubKey =
-  OAuth2
-    { oauthClientId = "xxxxxxxxxxxxxxx",
-      oauthClientSecret = Just "xxxxxxxxxxxxxxxxxxxxxx",
-      oauthCallback = Just [uri|http://127.0.0.1:9988/githubCallback|],
-      oauthOAuthorizeEndpoint = [uri|https://github.com/login/oauth/authorize|],
-      oauthAccessTokenEndpoint =
-        [uri|https://github.com/login/oauth/access_token|]
-    }
+githubKey = OAuth2
+  { oauthClientId            = "xxxxxxxxxxxxxxx"
+  , oauthClientSecret        = Just "xxxxxxxxxxxxxxxxxxxxxx"
+  , oauthCallback            = Just [uri|http://127.0.0.1:9988/githubCallback|]
+  , oauthOAuthorizeEndpoint  = [uri|https://github.com/login/oauth/authorize|]
+  , oauthAccessTokenEndpoint =
+    [uri|https://github.com/login/oauth/access_token|]
+  }
 
 -- | oauthCallback = Just "https://developers.google.com/oauthplayground"
 googleKey :: OAuth2
-googleKey =
-  OAuth2
-    { oauthClientId = "xxxxxxxxxxxxxxx.apps.googleusercontent.com",
-      oauthClientSecret = Just "xxxxxxxxxxxxxxxxxxxxxx",
-      oauthCallback = Just [uri|http://127.0.0.1:9988/googleCallback|],
-      oauthOAuthorizeEndpoint = [uri|https://accounts.google.com/o/oauth2/auth|],
-      oauthAccessTokenEndpoint = [uri|https://www.googleapis.com/oauth2/v3/token|]
-    }
+googleKey = OAuth2
+  { oauthClientId            = "xxxxxxxxxxxxxxx.apps.googleusercontent.com"
+  , oauthClientSecret        = Just "xxxxxxxxxxxxxxxxxxxxxx"
+  , oauthCallback            = Just [uri|http://127.0.0.1:9988/googleCallback|]
+  , oauthOAuthorizeEndpoint  = [uri|https://accounts.google.com/o/oauth2/auth|]
+  , oauthAccessTokenEndpoint = [uri|https://www.googleapis.com/oauth2/v3/token|]
+  }
 
 facebookKey :: OAuth2
-facebookKey =
-  OAuth2
-    { oauthClientId = "xxxxxxxxxxxxxxx",
-      oauthClientSecret = Just "xxxxxxxxxxxxxxxxxxxxxx",
-      oauthCallback = Just [uri|http://t.haskellcn.org/cb|],
-      oauthOAuthorizeEndpoint = [uri|https://www.facebook.com/dialog/oauth|],
-      oauthAccessTokenEndpoint =
-        [uri|https://graph.facebook.com/v2.3/oauth/access_token|]
-    }
+facebookKey = OAuth2
+  { oauthClientId            = "xxxxxxxxxxxxxxx"
+  , oauthClientSecret        = Just "xxxxxxxxxxxxxxxxxxxxxx"
+  , oauthCallback            = Just [uri|http://t.haskellcn.org/cb|]
+  , oauthOAuthorizeEndpoint  = [uri|https://www.facebook.com/dialog/oauth|]
+  , oauthAccessTokenEndpoint =
+    [uri|https://graph.facebook.com/v2.3/oauth/access_token|]
+  }
 
 doubanKey :: OAuth2
-doubanKey =
-  OAuth2
-    { oauthClientId = "xxxxxxxxxxxxxxx",
-      oauthClientSecret = Just "xxxxxxxxxxxxxxxxxxxxxx",
-      oauthCallback = Just [uri|http://localhost:9999/oauthCallback|],
-      oauthOAuthorizeEndpoint = [uri|https://www.douban.com/service/auth2/auth|],
-      oauthAccessTokenEndpoint = [uri|https://www.douban.com/service/auth2/token|]
-    }
+doubanKey = OAuth2
+  { oauthClientId            = "xxxxxxxxxxxxxxx"
+  , oauthClientSecret        = Just "xxxxxxxxxxxxxxxxxxxxxx"
+  , oauthCallback            = Just [uri|http://localhost:9999/oauthCallback|]
+  , oauthOAuthorizeEndpoint  = [uri|https://www.douban.com/service/auth2/auth|]
+  , oauthAccessTokenEndpoint = [uri|https://www.douban.com/service/auth2/token|]
+  }
 
 fitbitKey :: OAuth2
-fitbitKey =
-  OAuth2
-    { oauthClientId = "xxxxxx",
-      oauthClientSecret = Just "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx",
-      oauthCallback = Just [uri|http://localhost:9988/oauth2/callback|],
-      oauthOAuthorizeEndpoint = [uri|https://www.fitbit.com/oauth2/authorize|],
-      oauthAccessTokenEndpoint = [uri|https://api.fitbit.com/oauth2/token|]
-    }
+fitbitKey = OAuth2
+  { oauthClientId            = "xxxxxx"
+  , oauthClientSecret        = Just "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
+  , oauthCallback            = Just [uri|http://localhost:9988/oauth2/callback|]
+  , oauthOAuthorizeEndpoint  = [uri|https://www.fitbit.com/oauth2/authorize|]
+  , oauthAccessTokenEndpoint = [uri|https://api.fitbit.com/oauth2/token|]
+  }
 
 -- fix key from your application edit page
 -- https://stackapps.com/apps/oauth
@@ -77,76 +71,59 @@
 stackexchangeAppKey = "xxxxxx"
 
 stackexchangeKey :: OAuth2
-stackexchangeKey =
-  OAuth2
-    { oauthClientId = "xx",
-      oauthClientSecret = Just "xxxxxxxxxxxxxxx",
-      oauthCallback = Just [uri|http://c.haskellcn.org/cb|],
-      oauthOAuthorizeEndpoint = [uri|https://stackexchange.com/oauth|],
-      oauthAccessTokenEndpoint =
-        [uri|https://stackexchange.com/oauth/access_token|]
-    }
-
+stackexchangeKey = OAuth2
+  { oauthClientId            = "xx"
+  , oauthClientSecret        = Just "xxxxxxxxxxxxxxx"
+  , oauthCallback            = Just [uri|http://c.haskellcn.org/cb|]
+  , oauthOAuthorizeEndpoint  = [uri|https://stackexchange.com/oauth|]
+  , oauthAccessTokenEndpoint =
+    [uri|https://stackexchange.com/oauth/access_token|]
+  }
 dropboxKey :: OAuth2
-dropboxKey =
-  OAuth2
-    { oauthClientId = "xxx",
-      oauthClientSecret = Just "xxx",
-      oauthCallback = Just [uri|http://localhost:9988/oauth2/callback|],
-      oauthOAuthorizeEndpoint = [uri|https://www.dropbox.com/1/oauth2/authorize|],
-      oauthAccessTokenEndpoint = [uri|https://api.dropboxapi.com/oauth2/token|]
-    }
+dropboxKey = OAuth2
+  { oauthClientId            = "xxx"
+  , oauthClientSecret        = Just "xxx"
+  , oauthCallback            = Just [uri|http://localhost:9988/oauth2/callback|]
+  , oauthOAuthorizeEndpoint  = [uri|https://www.dropbox.com/1/oauth2/authorize|]
+  , oauthAccessTokenEndpoint = [uri|https://api.dropboxapi.com/oauth2/token|]
+  }
 
 oktaKey :: OAuth2
-oktaKey =
-  OAuth2
-    { oauthClientId = "0oa54gpOiDEZTA2rk0g4",
-      oauthClientSecret = Just "0_Vo1pBmK6tOSl25V1mEOyGDunakBCBDFGnCvHcF",
-      oauthCallback = Just [uri|http://localhost:9988/oauth2/callback|],
-      oauthOAuthorizeEndpoint =
-        [uri|http://rain.okta1.com:1802/oauth2/v1/authorize|],
-      oauthAccessTokenEndpoint = [uri|http://rain.okta1.com:1802/oauth2/v1/token|]
-    }
-
-oktaKey1 :: OAuth2
-oktaKey1 =
-  OAuth2
-    { oauthClientId = "0oa3pfim3hCbfCqaw0g7",
-      oauthClientSecret = Just "sc0J-DXuJgB3sApT3xMr6_jS2kJ6QXhp3RxBTszo",
-      oauthCallback = Just [uri|http://localhost:9988/oauth2/callback|],
-      oauthOAuthorizeEndpoint =
-        [uri|https://hw2.trexcloud.com/oauth2/v1/authorize|],
-      oauthAccessTokenEndpoint = [uri|https://hw2.trexcloud.com/oauth2/v1/token|]
-    }
+oktaKey = OAuth2
+  { oauthClientId            = "xxx"
+  , oauthClientSecret        = Just "xxx"
+  , oauthCallback            = Just [uri|http://localhost:9988/oauth2/callback|]
+  , oauthOAuthorizeEndpoint  =
+    [uri|https://dev-148986.oktapreview.com/oauth2/v1/authorize|]
+  , oauthAccessTokenEndpoint =
+    [uri|https://dev-148986.oktapreview.com/oauth2/v1/token|]
+  }
 
 azureADKey :: OAuth2
-azureADKey =
-  OAuth2
-    { oauthClientId = "xxx",
-      oauthClientSecret = Just "xxx",
-      oauthCallback = Just [uri|http://localhost:9988/oauth2/callback|],
-      oauthOAuthorizeEndpoint =
-        [uri|https://login.windows.net/common/oauth2/authorize|],
-      oauthAccessTokenEndpoint =
-        [uri|https://login.windows.net/common/oauth2/token|]
-    }
+azureADKey = OAuth2
+  { oauthClientId            = "xxx"
+  , oauthClientSecret        = Just "xxx"
+  , oauthCallback            = Just [uri|http://localhost:9988/oauth2/callback|]
+  , oauthOAuthorizeEndpoint  =
+    [uri|https://login.windows.net/common/oauth2/authorize|]
+  , oauthAccessTokenEndpoint =
+    [uri|https://login.windows.net/common/oauth2/token|]
+  }
 
 zohoKey :: OAuth2
-zohoKey =
-  OAuth2
-    { oauthClientId = "xxx",
-      oauthClientSecret = Just "xxx",
-      oauthCallback = Just [uri|http://localhost:9988/oauth2/callback|],
-      oauthOAuthorizeEndpoint = [uri|https://accounts.zoho.com/oauth/v2/auth|],
-      oauthAccessTokenEndpoint = [uri|https://accounts.zoho.com/oauth/v2/token|]
-    }
+zohoKey = OAuth2
+  { oauthClientId            = "xxx"
+  , oauthClientSecret        = Just "xxx"
+  , oauthCallback            = Just [uri|http://localhost:9988/oauth2/callback|]
+  , oauthOAuthorizeEndpoint  = [uri|https://accounts.zoho.com/oauth/v2/auth|]
+  , oauthAccessTokenEndpoint = [uri|https://accounts.zoho.com/oauth/v2/token|]
+  }
 
 auth0Key :: OAuth2
-auth0Key =
-  OAuth2
-    { oauthClientId = "tmEEsqOamfVZM3Z62vK91OQpmPQLlMAk",
-      oauthClientSecret = Just "6JA_iHEjsVqsLemAMRLoUaOvL-tJSjA31o0h6qt-dXcLEfe0OSLwDHQDwX8kq3Hy",
-      oauthCallback = Just [uri|http://localhost:9988/oauth2/callback|],
-      oauthOAuthorizeEndpoint = [uri|https://freizl.auth0.com/authorize|],
-      oauthAccessTokenEndpoint = [uri|https://freizl.auth0.com/oauth/token|]
-    }
+auth0Key = OAuth2
+  { oauthClientId            = "xxx"
+  , oauthClientSecret        = Just "xxx"
+  , oauthCallback            = Just [uri|http://localhost:9988/oauth2/callback|]
+  , oauthOAuthorizeEndpoint  = [uri|https://foo.auth0.com/authorize|]
+  , oauthAccessTokenEndpoint = [uri|https://foo.auth0.com/oauth/token|]
+  }
diff --git a/hoauth2.cabal b/hoauth2.cabal
--- a/hoauth2.cabal
+++ b/hoauth2.cabal
@@ -1,7 +1,7 @@
 Cabal-version: 2.4
 Name:                hoauth2
 -- http://wiki.haskell.org/Package_versioning_policy
-Version:             1.16.1
+Version:             1.16.2
 
 Synopsis:            Haskell OAuth2 authentication client
 
@@ -132,7 +132,7 @@
                        microlens            >= 0.4.0 && < 0.5,
                        unordered-containers >= 0.2.5,
                        wai-middleware-static >= 0.8.1 && < 0.10.0,
-                       mustache >= 2.2.3 && < 2.4.0,
+                       mustache >= 2.2.3 && < 2.5.0,
                        scotty >= 0.10.0 && < 0.13,
                        binary >= 0.8.3.0 && < 0.8.9,
                        parsec >= 3.1.11 && < 3.2.0 ,