``ReferenceManyCollection`` also has this method, so I guess the correct fix would be:
```
diff --git a/lib/Doctrine/ODM/PHPCR/UnitOfWork.php b/lib/Doctrine/ODM/PHPCR/UnitOfWork.php
index dbd06e3..b69481f 100644
--- a/lib/Doctrine/ODM/PHPCR/UnitOfWork.php
+++ b/lib/Doctrine/ODM/PHPCR/UnitOfWork.php
@@ -1081,9 +1081,10 @@ class UnitOfWork
                         }
                     }
 
-                    if (!$isNew && $mapping['cascade'] & ClassMetadata::CASCADE_REMOVE
-                        && (is_array($this->originalData[$oid][$fieldName])
-                            || $this->originalData[$oid][$fieldName] instanceof Collection
+                    if (!$isNew
+                        && $mapping['cascade'] & ClassMetadata::CASCADE_REMOVE
+                        && ($this->originalData[$oid][$fieldName] instanceof ReferenceManyCollection
+                            || $this->originalData[$oid][$fieldName] instanceof ReferrersCollection
                         )
                     ) {
                         $associations = $this->originalData[$oid][$fieldName]->getOriginalPaths();
```