diff --git a/src/Entities/Interfaces/ClientEntityInterface.php b/src/Entities/Interfaces/ClientEntityInterface.php
index 4ed17162..7fde09d9 100644
--- a/src/Entities/Interfaces/ClientEntityInterface.php
+++ b/src/Entities/Interfaces/ClientEntityInterface.php
@@ -40,9 +40,11 @@ interface ClientEntityInterface
     public function setRedirectUri($redirectUri);
 
     /**
-     * Returns the registered redirect URI.
+     * Returns the registered redirect URI (as a string).
      *
-     * @return string
+     * Alternatively return an indexed array of redirect URIs.
+     *
+     * @return string|string[]
      */
     public function getRedirectUri();
 }
diff --git a/src/Grant/AbstractGrant.php b/src/Grant/AbstractGrant.php
index 14a46e35..f68913d8 100644
--- a/src/Grant/AbstractGrant.php
+++ b/src/Grant/AbstractGrant.php
@@ -173,8 +173,18 @@ abstract class AbstractGrant implements GrantTypeInterface
 
         // If a redirect URI is provided ensure it matches what is pre-registered
         $redirectUri = $this->getRequestParameter('redirect_uri', $request, null);
-        if ($redirectUri !== null && (strcmp($client->getRedirectUri(), $redirectUri) !== 0)) {
-            throw OAuthServerException::invalidClient();
+        if ($redirectUri !== null) {
+            if (
+                is_string($client->getRedirectUri())
+                && (strcmp($client->getRedirectUri(), $redirectUri) !== 0)
+            ) {
+                throw OAuthServerException::invalidClient();
+            } elseif (
+                is_array($client->getRedirectUri())
+                && in_array($redirectUri, $client->getRedirectUri()) === false
+            ) {
+                throw OAuthServerException::invalidClient();
+            }
         }
 
         return $client;
diff --git a/tests/Grant/AbstractGrantTest.php b/tests/Grant/AbstractGrantTest.php
index 1161ebc4..cdde8764 100644
--- a/tests/Grant/AbstractGrantTest.php
+++ b/tests/Grant/AbstractGrantTest.php
@@ -185,6 +185,34 @@ class AbstractGrantTest extends \PHPUnit_Framework_TestCase
         $validateClientMethod->invoke($grantMock, $serverRequest, true, true);
     }
 
+    /**
+     * @expectedException \League\OAuth2\Server\Exception\OAuthServerException
+     */
+    public function testValidateClientInvalidRedirectUriArray()
+    {
+        $client = new ClientEntity();
+        $client->setRedirectUri(['http://foo/bar']);
+        $clientRepositoryMock = $this->getMockBuilder(ClientRepositoryInterface::class)->getMock();
+        $clientRepositoryMock->method('getClientEntity')->willReturn($client);
+
+        /** @var AbstractGrant $grantMock */
+        $grantMock = $this->getMockForAbstractClass(AbstractGrant::class);
+        $grantMock->setClientRepository($clientRepositoryMock);
+
+        $abstractGrantReflection = new \ReflectionClass($grantMock);
+
+        $serverRequest = new ServerRequest();
+        $serverRequest = $serverRequest->withParsedBody([
+            'client_id'     => 'foo',
+            'redirect_uri'  => 'http://bar/foo',
+        ]);
+
+        $validateClientMethod = $abstractGrantReflection->getMethod('validateClient');
+        $validateClientMethod->setAccessible(true);
+
+        $validateClientMethod->invoke($grantMock, $serverRequest, true, true);
+    }
+
     /**
      * @expectedException \League\OAuth2\Server\Exception\OAuthServerException
      */