diff --git a/LICENSE b/LICENSE
--- a/LICENSE
+++ b/LICENSE
@@ -1,30 +1,21 @@
-Copyright (c)2012-present, Haisheng Wu
-
-All rights reserved.
-
-Redistribution and use in source and binary forms, with or without
-modification, are permitted provided that the following conditions are met:
+MIT License
 
-    * Redistributions of source code must retain the above copyright
-      notice, this list of conditions and the following disclaimer.
+Copyright (c) 2022 Haisheng Wu
 
-    * Redistributions in binary form must reproduce the above
-      copyright notice, this list of conditions and the following
-      disclaimer in the documentation and/or other materials provided
-      with the distribution.
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
 
-    * Neither the name of Haisheng Wu nor the names of other
-      contributors may be used to endorse or promote products derived
-      from this software without specific prior written permission.
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
 
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/hoauth2-tutorial.cabal b/hoauth2-tutorial.cabal
--- a/hoauth2-tutorial.cabal
+++ b/hoauth2-tutorial.cabal
@@ -1,11 +1,12 @@
 cabal-version: 2.4
 name:          hoauth2-tutorial
-version:       0.1.1
+version:       0.1.2
 synopsis:      Tutorial for using hoauth2
 description:
   Tutorial to demostrate how to use hoauth2 to implement OAuth2 flow in an web Application.
+
 homepage:      https://github.com/freizl/hoauth2
-license:       BSD-3-Clause
+license:       MIT
 license-file:  LICENSE
 author:        Haisheng Wu
 maintainer:    Haisheng Wu <freizl@gmail.com>
@@ -30,7 +31,7 @@
     , aeson           >=2.0    && <2.2
     , base            >=4.5    && <5
     , bytestring      >=0.9    && <0.12
-    , hoauth2         ^>= 2.5
+    , hoauth2         >=2.5
     , http-conduit    >=2.1    && <2.4
     , http-types      >=0.11   && <0.13
     , scotty          >=0.10.0 && <0.13
@@ -54,7 +55,7 @@
   -- LANGUAGE extensions used by modules in this package.
   -- other-extensions:
   build-depends:
-    , base            >=4.5    && <5
+    , base              >=4.5 && <5
     , hoauth2-tutorial
 
   hs-source-dirs:   app
diff --git a/src/HOAuth2Tutorial.hs b/src/HOAuth2Tutorial.hs
--- a/src/HOAuth2Tutorial.hs
+++ b/src/HOAuth2Tutorial.hs
@@ -109,11 +109,7 @@
 import Control.Monad (void)
 import Control.Monad.IO.Class (liftIO)
 import Control.Monad.Trans.Except
-import Data.Aeson
-  ( FromJSON (parseJSON),
-    defaultOptions,
-    genericParseJSON,
-  )
+import Data.Aeson (FromJSON)
 import Data.ByteString.Char8 qualified as BS
 import Data.ByteString.Lazy.Char8 qualified as BSL
 import Data.IORef (IORef, newIORef, readIORef, writeIORef)
@@ -164,7 +160,7 @@
     ]
     $ authorizationUrl auth0
 
--- | You'll need to find out an better to create @state@
+-- | You'll need to find out an better way to create @state@
 -- which is recommended in <https://www.rfc-editor.org/rfc/rfc6749#section-10.12>
 randomStateValue :: BS.ByteString
 randomStateValue = "random-state-to-prevent-csrf"
@@ -182,8 +178,7 @@
   }
   deriving (Show, Generic)
 
-instance FromJSON Auth0User where
-  parseJSON = genericParseJSON defaultOptions
+instance FromJSON Auth0User
 
 ------------------------------