Index: tests/Zend/Oauth/OauthTest.php
===================================================================
--- tests/Zend/Oauth/OauthTest.php	(revision 23572)
+++ tests/Zend/Oauth/OauthTest.php	(working copy)
@@ -70,4 +70,44 @@
         $this->assertEquals('GET', $client->getRequestMethod());
         $this->assertEquals('http://www.example.com', $client->getSiteUrl());
     }
+
+    /**
+     * @group ZF-10851
+     */
+    public function testOauthClientAcceptsRealmConfigurationOption()
+    {
+        $options = array(
+            'realm'			=> 'http://www.example.com'
+        );
+
+        require_once 'Zend/Oauth/Client.php';
+        $client = new Zend_Oauth_Client($options);
+        $this->assertEquals('http://www.example.com', $client->getRealm());
+    }
+
+    /**
+     * @group ZF-10851
+     */
+    public function testOauthClientPreparationWithRealmConfigurationOption()
+    {
+        require_once "Zend/Oauth/Token/Access.php";
+        
+        $options = array(
+            'requestMethod' => 'GET',
+            'siteUrl'       => 'http://www.example.com',
+            'realm'			=> 'someRealm'
+        );
+        $token = new Zend_Oauth_Token_Access();
+
+        require_once 'Zend/Oauth/Client.php';
+        $client = new Zend_Oauth_Client($options);
+        $this->assertEquals(NULL,$client->getHeader('Authorization'));
+        
+        $client->setToken($token);
+        $client->setUri('http://oauth.example.com');
+        $client->prepareOauth();
+        
+        $this->assertNotContains('realm=""',$client->getHeader('Authorization'));
+        $this->assertContains('realm="someRealm"',$client->getHeader('Authorization'));
+    }
 }
Index: library/Zend/Oauth/Client.php
===================================================================
--- library/Zend/Oauth/Client.php	(revision 23572)
+++ library/Zend/Oauth/Client.php	(working copy)
@@ -246,7 +246,8 @@
             $oauthHeaderValue = $this->getToken()->toHeader(
                 $this->getUri(true),
                 $this->_config,
-                $this->_getSignableParametersAsQueryString()
+                $this->_getSignableParametersAsQueryString(),
+                $this->getRealm()
             );
             $this->setHeaders('Authorization', $oauthHeaderValue);
         } elseif ($requestScheme == Zend_Oauth::REQUEST_SCHEME_POSTBODY) {
Index: library/Zend/Oauth/Config.php
===================================================================
--- library/Zend/Oauth/Config.php	(revision 23572)
+++ library/Zend/Oauth/Config.php	(working copy)
@@ -146,6 +146,13 @@
      * @var Zend_Oauth_Token
      */
     protected $_token = null;
+    
+    /**
+     * Define the OAuth realm
+     * 
+     * @var string
+     */
+    protected $_realm = null;
 
     /**
      * Constructor; create a new object with an optional array|Zend_Config
@@ -214,6 +221,9 @@
                 case 'rsaPublicKey':
                     $this->setRsaPublicKey($value);
                     break;
+                case 'realm':
+                    $this->setRealm($value);
+                    break;
             }
         }
         if (isset($options['requestScheme'])) {
@@ -655,4 +665,26 @@
     {
         return $this->_token;
     }
+
+    /**
+     * Set OAuth realm
+     *
+     * @param  string $realm
+     * @return Zend_Oauth_Config
+     */
+    public function setRealm($realm)
+    {
+        $this->_realm = $realm;
+        return $this;
+    }
+
+    /**
+     * Get OAuth realm
+     *
+     * @return string
+     */
+    public function getRealm()
+    {
+        return $this->_realm;
+    }
 }
Index: library/Zend/Oauth/Config/ConfigInterface.php
===================================================================
--- library/Zend/Oauth/Config/ConfigInterface.php	(revision 23572)
+++ library/Zend/Oauth/Config/ConfigInterface.php	(working copy)
@@ -72,4 +72,8 @@
     public function setToken(Zend_Oauth_Token $token);
 
     public function getToken();
+
+    public function setRealm($realm);
+
+    public function getRealm();
 }