diff --git a/lib/Doctrine/ORM/Tools/Setup.php b/lib/Doctrine/ORM/Tools/Setup.php
index 11992a96e..79d4670ad 100644
--- a/lib/Doctrine/ORM/Tools/Setup.php
+++ b/lib/Doctrine/ORM/Tools/Setup.php
@@ -21,6 +21,7 @@ namespace Doctrine\ORM\Tools;
 
 use Doctrine\Common\ClassLoader;
 use Doctrine\Common\Cache\Cache;
+use Doctrine\Common\Cache\CacheProvider;
 use Doctrine\Common\Cache\ArrayCache;
 use Doctrine\ORM\Configuration;
 use Doctrine\ORM\Mapping\Driver\XmlDriver;
@@ -144,7 +145,9 @@ class Setup
             $cache = new ArrayCache();
         }
 
-        $cache->setNamespace("dc2_" . md5($proxyDir) . "_"); // to avoid collisions
+        if ($cache instanceof CacheProvider) {
+            $cache->setNamespace("dc2_" . md5($proxyDir) . "_"); // to avoid collisions
+        }
 
         $config = new Configuration();
         $config->setMetadataCacheImpl($cache);
diff --git a/tests/Doctrine/Tests/ORM/Tools/SetupTest.php b/tests/Doctrine/Tests/ORM/Tools/SetupTest.php
index 3a6055f1e..20ad5ee0a 100644
--- a/tests/Doctrine/Tests/ORM/Tools/SetupTest.php
+++ b/tests/Doctrine/Tests/ORM/Tools/SetupTest.php
@@ -89,4 +89,19 @@ class SetupTest extends \Doctrine\Tests\OrmTestCase
         $this->assertSame($cache, $config->getMetadataCacheImpl());
         $this->assertSame($cache, $config->getQueryCacheImpl());
     }
+
+    /**
+     * @group DDC-3190
+     */
+    public function testConfigureCacheCustomInstance()
+    {
+        $cache = $this->getMock('Doctrine\Common\Cache\Cache');
+        $cache->expects($this->never())->method('setNamespace');
+
+        $config = Setup::createConfiguration(array(), true, $cache);
+
+        $this->assertSame($cache, $config->getResultCacheImpl());
+        $this->assertSame($cache, $config->getMetadataCacheImpl());
+        $this->assertSame($cache, $config->getQueryCacheImpl());
+    }
 }