diff --git a/lib/doorkeeper/request/authorization_code.rb b/lib/doorkeeper/request/authorization_code.rb
index 092e2e9d3..9b5d74eec 100644
--- a/lib/doorkeeper/request/authorization_code.rb
+++ b/lib/doorkeeper/request/authorization_code.rb
@@ -1,19 +1,18 @@
+require 'doorkeeper/request/strategy'
+
 module Doorkeeper
   module Request
-    class AuthorizationCode
-      attr_accessor :grant, :client, :server
+    class AuthorizationCode < Strategy
+      attr_accessor :grant, :client
 
       def initialize(server)
-        @grant, @client, @server = server.grant, server.client, server
+        super
+        @grant, @client = server.grant, server.client
       end
 
       def request
         @request ||= OAuth::AuthorizationCodeRequest.new(Doorkeeper.configuration, grant, client, server.parameters)
       end
-
-      def authorize
-        request.authorize
-      end
     end
   end
 end
diff --git a/lib/doorkeeper/request/client_credentials.rb b/lib/doorkeeper/request/client_credentials.rb
index 8e46810cb..e65b3467e 100644
--- a/lib/doorkeeper/request/client_credentials.rb
+++ b/lib/doorkeeper/request/client_credentials.rb
@@ -1,19 +1,18 @@
+require 'doorkeeper/request/strategy'
+
 module Doorkeeper
   module Request
-    class ClientCredentials
-      attr_accessor :client, :server
+    class ClientCredentials < Strategy
+      attr_accessor :client
 
       def initialize(server)
-        @client, @server = server.client, server
+        super
+        @client = server.client
       end
 
       def request
         @request ||= OAuth::ClientCredentialsRequest.new(Doorkeeper.configuration, client, server.parameters)
       end
-
-      def authorize
-        request.authorize
-      end
     end
   end
 end
diff --git a/lib/doorkeeper/request/code.rb b/lib/doorkeeper/request/code.rb
index 6fea02b58..c3e045c6e 100644
--- a/lib/doorkeeper/request/code.rb
+++ b/lib/doorkeeper/request/code.rb
@@ -1,20 +1,18 @@
+require 'doorkeeper/request/strategy'
+
 module Doorkeeper
   module Request
-    class Code
-      attr_accessor :pre_auth, :server
+    class Code < Strategy
+      attr_accessor :pre_auth
 
       def initialize(server)
+        super
         @pre_auth = server.context.send(:pre_auth)
-        @server = server
       end
 
       def request
         @request ||= OAuth::CodeRequest.new(pre_auth, server.current_resource_owner)
       end
-
-      def authorize
-        request.authorize
-      end
     end
   end
 end
diff --git a/lib/doorkeeper/request/password.rb b/lib/doorkeeper/request/password.rb
index 26d5aa166..977eb0fa3 100644
--- a/lib/doorkeeper/request/password.rb
+++ b/lib/doorkeeper/request/password.rb
@@ -1,21 +1,19 @@
+require 'doorkeeper/request/strategy'
+
 module Doorkeeper
   module Request
-    class Password
-      attr_accessor :credentials, :resource_owner, :server
+    class Password < Strategy
+      attr_accessor :credentials, :resource_owner
 
       def initialize(server)
+        super
         @credentials = server.credentials
         @resource_owner = server.resource_owner
-        @server = server
       end
 
       def request
         @request ||= OAuth::PasswordAccessTokenRequest.new(Doorkeeper.configuration, credentials, resource_owner, server.parameters)
       end
-
-      def authorize
-        request.authorize
-      end
     end
   end
 end
diff --git a/lib/doorkeeper/request/refresh_token.rb b/lib/doorkeeper/request/refresh_token.rb
index d85be9366..159b45d34 100644
--- a/lib/doorkeeper/request/refresh_token.rb
+++ b/lib/doorkeeper/request/refresh_token.rb
@@ -1,21 +1,19 @@
+require 'doorkeeper/request/strategy'
+
 module Doorkeeper
   module Request
-    class RefreshToken
-      attr_accessor :refresh_token, :credentials, :server
+    class RefreshToken < Strategy
+      attr_accessor :refresh_token, :credentials
 
       def initialize(server)
+        super
         @refresh_token = server.current_refresh_token
         @credentials = server.credentials
-        @server = server
       end
 
       def request
         @request ||= OAuth::RefreshTokenRequest.new(Doorkeeper.configuration, refresh_token, credentials, server.parameters)
       end
-
-      def authorize
-        request.authorize
-      end
     end
   end
 end
diff --git a/lib/doorkeeper/request/strategy.rb b/lib/doorkeeper/request/strategy.rb
new file mode 100644
index 000000000..a1fd13551
--- /dev/null
+++ b/lib/doorkeeper/request/strategy.rb
@@ -0,0 +1,19 @@
+module Doorkeeper
+  module Request
+    class Strategy
+      attr_accessor :server
+
+      def initialize(server)
+        self.server = server
+      end
+
+      def request
+        raise NotImplementedError, "request strategies must define #request"
+      end
+
+      def authorize
+        request.authorize
+      end
+    end
+  end
+end
diff --git a/lib/doorkeeper/request/token.rb b/lib/doorkeeper/request/token.rb
index b938d2174..55e398d44 100644
--- a/lib/doorkeeper/request/token.rb
+++ b/lib/doorkeeper/request/token.rb
@@ -1,20 +1,18 @@
+require 'doorkeeper/request/strategy'
+
 module Doorkeeper
   module Request
-    class Token
-      attr_accessor :pre_auth, :server
+    class Token < Strategy
+      attr_accessor :pre_auth
 
       def initialize(server)
+        super
         @pre_auth = server.context.send(:pre_auth)
-        @server = server
       end
 
       def request
         @request ||= OAuth::TokenRequest.new(pre_auth, server.current_resource_owner)
       end
-
-      def authorize
-        request.authorize
-      end
     end
   end
 end