diff --git a/src/JacobKiers/OAuth/HmacSha1.php b/src/JacobKiers/OAuth/HmacSha1.php
index cbe6c15..7fc823d 100644
--- a/src/JacobKiers/OAuth/HmacSha1.php
+++ b/src/JacobKiers/OAuth/HmacSha1.php
@@ -46,13 +46,13 @@ class HmacSha1 extends SignatureMethod
      * Please note that the second encoding MUST NOT happen in the SignatureMethod, as
      * OAuthRequest handles this!
      *
-     * @param JacobKiers\OAuth\Request $request
+     * @param JacobKiers\OAuth\RequestInterface $request
      * @param JacobKiers\OAuth\Client  $client
      * @param JacobKiers\OAuth\Token   $token
      *
      * @return string
      */
-    public function buildSignature(Request $request, Client $client, Token $token = null)
+    public function buildSignature(RequestInterface $request, Client $client, Token $token = null)
     {
         $base_string = $request->getOAuthSignatureBaseString();
         $key = $this->getSignatureKey($client, $token);
diff --git a/src/JacobKiers/OAuth/PlainText.php b/src/JacobKiers/OAuth/PlainText.php
index 38525a8..fce18e6 100644
--- a/src/JacobKiers/OAuth/PlainText.php
+++ b/src/JacobKiers/OAuth/PlainText.php
@@ -44,13 +44,13 @@ class PlainText extends SignatureMethod
      * Please note that the second encoding MUST NOT happen in the SignatureMethod, as
      * OAuthRequest handles this!
      *
-     * @param JacobKiers\OAuth\Request $request
+     * @param JacobKiers\OAuth\RequestInterface $request
      * @param JacobKiers\OAuth\Client  $client
      * @param JacobKiers\OAuth\Token   $token
      *
      * @return string
      */
-    public function buildSignature(Request $request, Client $client, Token $token = null)
+    public function buildSignature(RequestInterface $request, Client $client, Token $token = null)
     {
         return $this->getSignatureKey($client, $token);
     }
diff --git a/src/JacobKiers/OAuth/Request.php b/src/JacobKiers/OAuth/Request.php
index 5e83365..20ef04f 100644
--- a/src/JacobKiers/OAuth/Request.php
+++ b/src/JacobKiers/OAuth/Request.php
@@ -79,7 +79,7 @@ class Request implements RequestInterface
      * @param string $http_url    Request URL.
      * @param array  $parameters  HTTP parameters.
      *
-     * @return JacobKiers\OAuth\Request
+     * @return JacobKiers\OAuth\RequestInterface
      */
     public static function fromRequest($http_method = null, $http_url = null, $parameters = null)
     {
@@ -137,7 +137,7 @@ class Request implements RequestInterface
      * @param string                 $http_url
      * @param array                  $parameters
      *
-     * @return JacobKiers\OAuth\Request
+     * @return JacobKiers\OAuth\RequestInterface
      */
     public static function fromClientAndToken(
         Client $client,
diff --git a/src/JacobKiers/OAuth/RsaSha1.php b/src/JacobKiers/OAuth/RsaSha1.php
index 994f141..5b14b7b 100644
--- a/src/JacobKiers/OAuth/RsaSha1.php
+++ b/src/JacobKiers/OAuth/RsaSha1.php
@@ -58,13 +58,13 @@ abstract class RsaSha1 extends SignatureMethod
     /**
      * Build up the signature.
      *
-     * @param JacobKiers\OAuth\Request $request
+     * @param JacobKiers\OAuth\RequestInterface $request
      * @param JacobKiers\OAuth\Client  $client
      * @param JacobKiers\OAuth\Token   $token
      *
      * @return string
      */
-    public function buildSignature(Request $request, Client $client, Token $token = null)
+    public function buildSignature(RequestInterface $request, Client $client, Token $token = null)
     {
         $base_string = $request->getOAuthSignatureBaseString();
 
@@ -86,14 +86,14 @@ abstract class RsaSha1 extends SignatureMethod
     /**
      * Verifies that a given signature is correct.
      *
-     * @param JacobKiers\OAuth\Request  $request
+     * @param JacobKiers\OAuth\RequestInterface  $request
      * @param JacobKiers\OAuth\Consumer $client
      * @param JacobKiers\OAuth\Token    $token
      * @param string                   $signature
      *
      * @return bool
      */
-    public function checkSignature(Request $request, Client $client, Token $token, $signature)
+    public function checkSignature(RequestInterface $request, Client $client, Token $token, $signature)
     {
         $base_string = $request->getOAuthSignatureBaseString();
 
diff --git a/src/JacobKiers/OAuth/Server.php b/src/JacobKiers/OAuth/Server.php
index ae23f4d..9dffdd4 100644
--- a/src/JacobKiers/OAuth/Server.php
+++ b/src/JacobKiers/OAuth/Server.php
@@ -77,7 +77,7 @@ class Server
      *
      * Returns the request token on success
      *
-     * @param JacobKiers\OAuth\RequestInterface $request
+     * @param JacobKiers\OAuth\RequestInterfaceInterface $request
      *
      * @return JacobKiers\OAuth\Token
      */
@@ -103,7 +103,7 @@ class Server
      *
      * Returns the access token on success.
      *
-     * @param JacobKiers\OAuth\RequestInterface $request
+     * @param JacobKiers\OAuth\RequestInterfaceInterface $request
      *
      * @return JacobKiers\OAuth\Token
      */
@@ -127,7 +127,7 @@ class Server
     /**
      * Verify an api call, checks all the parameters.
      *
-     * @param JacobKiers\OAuth\RequestInterface $request
+     * @param JacobKiers\OAuth\RequestInterfaceInterface $request
      *
      * @return array Client and Token
      */
@@ -145,7 +145,7 @@ class Server
     /**
      * Check that version is 1.0.
      *
-     * @param JacobKiers\OAuth\RequestInterface $request
+     * @param JacobKiers\OAuth\RequestInterfaceInterface $request
      *
      * @return string
      *
@@ -168,7 +168,7 @@ class Server
     /**
      * Get the signature method name, and if it is supported.
      *
-     * @param JacobKiers\OAuth\RequestInterface $request
+     * @param JacobKiers\OAuth\RequestInterfaceInterface $request
      *
      * @return string Signature method name.
      *
@@ -196,7 +196,7 @@ class Server
     /**
      * Try to find the client for the provided request's client key.
      *
-     * @param JacobKiers\OAuth\RequestInterface $request
+     * @param JacobKiers\OAuth\RequestInterfaceInterface $request
      *
      * @return JacobKiers\OAuth\Client
      *
@@ -221,7 +221,7 @@ class Server
     /**
      * Try to find the token for the provided request's token key.
      *
-     * @param JacobKiers\OAuth\RequestInterface $request
+     * @param JacobKiers\OAuth\RequestInterfaceInterface $request
      * @param JacobKiers\OAuth\Client  $client
      * @param string                   $token_type
      *
@@ -245,7 +245,7 @@ class Server
      *
      * Should determine the signature method appropriately
      *
-     * @param JacobKiers\OAuth\RequestInterface $request
+     * @param JacobKiers\OAuth\RequestInterfaceInterface $request
      * @param JacobKiers\OAuth\Client  $client
      * @param JacobKiers\OAuth\Token   $token
      *
diff --git a/src/JacobKiers/OAuth/SignatureMethod.php b/src/JacobKiers/OAuth/SignatureMethod.php
index 8ef2e6a..69cac4a 100644
--- a/src/JacobKiers/OAuth/SignatureMethod.php
+++ b/src/JacobKiers/OAuth/SignatureMethod.php
@@ -36,13 +36,13 @@ abstract class SignatureMethod
      * the encoding is handled in OAuthRequest when the final
      * request is serialized.
      *
-     * @param JacobKiers\OAuth\Request $request
+     * @param JacobKiers\OAuth\RequestInterface $request
      * @param JacobKiers\OAuth\Client  $client
      * @param JacobKiers\OAuth\Token   $token
      *
      * @return string
      */
-    abstract public function buildSignature(Request $request, Client $client, Token $token = null);
+    abstract public function buildSignature(RequestInterface $request, Client $client, Token $token = null);
 
     /**
      * Get the signature key, made up of client and optionally token shared secrets.
@@ -66,14 +66,14 @@ abstract class SignatureMethod
     /**
      * Verifies that a given signature is correct.
      *
-     * @param JacobKiers\OAuth\Request  $request
+     * @param JacobKiers\OAuth\RequestInterface  $request
      * @param JacobKiers\OAuth\Consumer $client
      * @param JacobKiers\OAuth\Token    $token
      * @param string                   $signature
      *
      * @return bool
      */
-    public function checkSignature(Request $request, Client $client, Token $token, $signature)
+    public function checkSignature(RequestInterface $request, Client $client, Token $token, $signature)
     {
         $built = $this->buildSignature($request, $client, $token);
         return $built == $signature;