diff --git a/lib/Doctrine/MongoDB/Collection.php b/lib/Doctrine/MongoDB/Collection.php
index 5d33c5a4..5e8e34b1 100644
--- a/lib/Doctrine/MongoDB/Collection.php
+++ b/lib/Doctrine/MongoDB/Collection.php
@@ -716,6 +716,12 @@ protected function doMapReduce($map, $reduce, array $out, array $query, array $o
             return new ArrayIterator($result['results']);
         }
 
+        if (isset($result['result']['db'], $result['result']['collection'])) {
+            return $this->connection
+                ->selectCollection($result['result']['db'], $result['result']['collection'])
+                ->find();
+        }
+
         return $this->database->selectCollection($result['result'])->find();
     }