diff --git a/src/GaryJones/OAuth/HmacSha1.php b/src/GaryJones/OAuth/HmacSha1.php
index 406573b..1a476c3 100644
--- a/src/GaryJones/OAuth/HmacSha1.php
+++ b/src/GaryJones/OAuth/HmacSha1.php
@@ -52,7 +52,7 @@ class HmacSha1 extends SignatureMethod
      *
      * @return string
      */
-    public function buildSignature(Request $request, Client $client, Token $token)
+    public function buildSignature(Request $request, Client $client, Token $token = null)
     {
         $base_string = $request->getSignatureBaseString();
         $request->base_string = $base_string;
diff --git a/src/GaryJones/OAuth/PlainText.php b/src/GaryJones/OAuth/PlainText.php
index febd407..5c4577c 100644
--- a/src/GaryJones/OAuth/PlainText.php
+++ b/src/GaryJones/OAuth/PlainText.php
@@ -50,7 +50,7 @@ class PlainText extends SignatureMethod
      *
      * @return string
      */
-    public function buildSignature(Request $request, Client $client, Token $token)
+    public function buildSignature(Request $request, Client $client, Token $token = null)
     {
         $key_parts = array(
             $client->getSecret(),
diff --git a/src/GaryJones/OAuth/RsaSha1.php b/src/GaryJones/OAuth/RsaSha1.php
index 100341e..9069554 100644
--- a/src/GaryJones/OAuth/RsaSha1.php
+++ b/src/GaryJones/OAuth/RsaSha1.php
@@ -33,7 +33,7 @@ abstract class RsaSha1 extends SignatureMethod
      */
     public function getName()
     {
-        return "RSA-SHA1";
+        return 'RSA-SHA1';
     }
 
     /**
@@ -64,7 +64,7 @@ abstract class RsaSha1 extends SignatureMethod
      *
      * @return string
      */
-    public function buildSignature(Request $request, Client $client, Token $token)
+    public function buildSignature(Request $request, Client $client, Token $token = null)
     {
         $base_string = $request->getSignatureBaseString();
         //$request->base_string = $base_string;
diff --git a/src/GaryJones/OAuth/SignatureMethod.php b/src/GaryJones/OAuth/SignatureMethod.php
index 415a205..df15f44 100644
--- a/src/GaryJones/OAuth/SignatureMethod.php
+++ b/src/GaryJones/OAuth/SignatureMethod.php
@@ -42,7 +42,7 @@ abstract class SignatureMethod
      *
      * @return string
      */
-    abstract public function buildSignature(Request $request, Client $client, Token $token);
+    abstract public function buildSignature(Request $request, Client $client, Token $token = null);
 
     /**
      * Verifies that a given signature is correct.