diff --git a/lib/Doctrine/ORM/Mapping/ClassMetadataFactory.php b/lib/Doctrine/ORM/Mapping/ClassMetadataFactory.php
index 089780775ba..0596e97462e 100644
--- a/lib/Doctrine/ORM/Mapping/ClassMetadataFactory.php
+++ b/lib/Doctrine/ORM/Mapping/ClassMetadataFactory.php
@@ -96,7 +96,6 @@ public function setEntityManager(EntityManagerInterface $em)
     protected function initialize()
     {
         $this->driver = $this->em->getConfiguration()->getMetadataDriverImpl();
-        $this->targetPlatform = $this->em->getConnection()->getDatabasePlatform();
         $this->evm = $this->em->getEventManager();
         $this->initialized = true;
     }
@@ -613,9 +612,9 @@ private function completeIdGeneratorMapping(ClassMetadataInfo $class)
     {
         $idGenType = $class->generatorType;
         if ($idGenType == ClassMetadata::GENERATOR_TYPE_AUTO) {
-            if ($this->targetPlatform->prefersSequences()) {
+            if ($this->getTargetPlatform()->prefersSequences()) {
                 $class->setIdGeneratorType(ClassMetadata::GENERATOR_TYPE_SEQUENCE);
-            } else if ($this->targetPlatform->prefersIdentityColumns()) {
+            } else if ($this->getTargetPlatform()->prefersIdentityColumns()) {
                 $class->setIdGeneratorType(ClassMetadata::GENERATOR_TYPE_IDENTITY);
             } else {
                 $class->setIdGeneratorType(ClassMetadata::GENERATOR_TYPE_TABLE);
@@ -629,13 +628,13 @@ private function completeIdGeneratorMapping(ClassMetadataInfo $class)
                 $fieldName    = $class->identifier ? $class->getSingleIdentifierFieldName() : null;
 
                 // Platforms that do not have native IDENTITY support need a sequence to emulate this behaviour.
-                if ($this->targetPlatform->usesSequenceEmulatedIdentityColumns()) {
+                if ($this->getTargetPlatform()->usesSequenceEmulatedIdentityColumns()) {
                     $columnName     = $class->getSingleIdentifierColumnName();
                     $quoted         = isset($class->fieldMappings[$fieldName]['quoted']) || isset($class->table['quoted']);
-                    $sequencePrefix = $class->getSequencePrefix($this->targetPlatform);
-                    $sequenceName   = $this->targetPlatform->getIdentitySequenceName($sequencePrefix, $columnName);
+                    $sequencePrefix = $class->getSequencePrefix($this->getTargetPlatform());
+                    $sequenceName   = $this->getTargetPlatform()->getIdentitySequenceName($sequencePrefix, $columnName);
                     $definition     = array(
-                        'sequenceName' => $this->targetPlatform->fixSchemaElementName($sequenceName)
+                        'sequenceName' => $this->getTargetPlatform()->fixSchemaElementName($sequenceName)
                     );
 
                     if ($quoted) {
@@ -646,7 +645,7 @@ private function completeIdGeneratorMapping(ClassMetadataInfo $class)
                         ->em
                         ->getConfiguration()
                         ->getQuoteStrategy()
-                        ->getSequenceName($definition, $class, $this->targetPlatform);
+                        ->getSequenceName($definition, $class, $this->getTargetPlatform());
                 }
 
                 $generator = ($fieldName && $class->fieldMappings[$fieldName]['type'] === 'bigint')
@@ -663,11 +662,11 @@ private function completeIdGeneratorMapping(ClassMetadataInfo $class)
 
                 if ( ! $definition) {
                     $fieldName      = $class->getSingleIdentifierFieldName();
-                    $sequenceName   = $class->getSequenceName($this->targetPlatform);
+                    $sequenceName   = $class->getSequenceName($this->getTargetPlatform());
                     $quoted         = isset($class->fieldMappings[$fieldName]['quoted']) || isset($class->table['quoted']);
 
                     $definition = array(
-                        'sequenceName'      => $this->targetPlatform->fixSchemaElementName($sequenceName),
+                        'sequenceName'      => $this->getTargetPlatform()->fixSchemaElementName($sequenceName),
                         'allocationSize'    => 1,
                         'initialValue'      => 1,
                     );
@@ -680,7 +679,7 @@ private function completeIdGeneratorMapping(ClassMetadataInfo $class)
                 }
 
                 $sequenceGenerator = new \Doctrine\ORM\Id\SequenceGenerator(
-                    $this->em->getConfiguration()->getQuoteStrategy()->getSequenceName($definition, $class, $this->targetPlatform),
+                    $this->em->getConfiguration()->getQuoteStrategy()->getSequenceName($definition, $class, $this->getTargetPlatform()),
                     $definition['allocationSize']
                 );
                 $class->setIdGenerator($sequenceGenerator);
@@ -753,4 +752,16 @@ protected function isEntity(ClassMetadataInterface $class)
     {
         return isset($class->isMappedSuperclass) && $class->isMappedSuperclass === false;
     }
+
+    /**
+     * @return Platforms\AbstractPlatform
+     */
+    private function getTargetPlatform()
+    {
+        if (!$this->targetPlatform) {
+            $this->targetPlatform = $this->em->getConnection()->getDatabasePlatform();
+        }
+
+        return $this->targetPlatform;
+    }
 }
diff --git a/tests/Doctrine/Tests/ORM/Mapping/ClassMetadataFactoryTest.php b/tests/Doctrine/Tests/ORM/Mapping/ClassMetadataFactoryTest.php
index cd17871ee63..855ff818ea1 100644
--- a/tests/Doctrine/Tests/ORM/Mapping/ClassMetadataFactoryTest.php
+++ b/tests/Doctrine/Tests/ORM/Mapping/ClassMetadataFactoryTest.php
@@ -194,15 +194,38 @@ public function testAddDefaultDiscriminatorMap()
         $rootMetadata = $cmf->getMetadataFor('Doctrine\Tests\Models\JoinedInheritanceType\RootClass');
     }
 
-    protected function _createEntityManager($metadataDriver)
+    public function testGetAllMetadataWorksWithBadConnection()
+    {
+        // DDC-3551
+        $conn = $this->getMockBuilder('Doctrine\DBAL\Connection')
+            ->disableOriginalConstructor()
+            ->getMock();
+        $mockDriver    = new MetadataDriverMock();
+        $em = $this->_createEntityManager($mockDriver, $conn);
+
+        $conn->expects($this->any())
+            ->method('getDatabasePlatform')
+            ->will($this->throwException(new \Exception('Exception thrown in test when calling getDatabasePlatform')));
+
+        $cmf = new ClassMetadataFactory();
+        $cmf->setEntityManager($em);
+
+        // getting all the metadata should work, even if get DatabasePlatform blows up
+        $metadata = $cmf->getAllMetadata();
+        // this will just be an empty array - there was no error
+        $this->assertEquals(array(), $metadata);
+    }
+
+    protected function _createEntityManager($metadataDriver, $conn = null)
     {
         $driverMock = new DriverMock();
         $config = new \Doctrine\ORM\Configuration();
         $config->setProxyDir(__DIR__ . '/../../Proxies');
         $config->setProxyNamespace('Doctrine\Tests\Proxies');
         $eventManager = new EventManager();
-        $conn = new ConnectionMock(array(), $driverMock, $config, $eventManager);
-        $mockDriver = new MetadataDriverMock();
+        if (!$conn) {
+            $conn = new ConnectionMock(array(), $driverMock, $config, $eventManager);
+        }
         $config->setMetadataDriverImpl($metadataDriver);
 
         return EntityManagerMock::create($conn, $config, $eventManager);