diff --git a/src/applications/differential/storage/DifferentialComment.php b/src/applications/differential/storage/DifferentialComment.php
index 66c22cd0fe..e5ee912957 100644
--- a/src/applications/differential/storage/DifferentialComment.php
+++ b/src/applications/differential/storage/DifferentialComment.php
@@ -1,156 +1,162 @@
 <?php
 
 final class DifferentialComment extends DifferentialDAO
   implements PhabricatorMarkupInterface {
 
   const METADATA_ADDED_REVIEWERS   = 'added-reviewers';
   const METADATA_REMOVED_REVIEWERS = 'removed-reviewers';
   const METADATA_ADDED_CCS         = 'added-ccs';
   const METADATA_DIFF_ID           = 'diff-id';
 
   const MARKUP_FIELD_BODY          = 'markup:body';
 
   protected $authorPHID;
   protected $revisionID;
   protected $action;
   protected $content = '';
   protected $cache;
   protected $metadata = array();
   protected $contentSource;
 
   private $arbitraryDiffForFacebook;
   private $proxyComment;
 
+  public function __clone() {
+    if ($this->proxyComment) {
+      $this->proxyComment = clone $this->proxyComment;
+    }
+  }
+
   public function getContent() {
     return $this->getProxyComment()->getContent();
   }
 
   public function setContent($content) {
     // NOTE: We no longer read this field, but there's no cost to continuing
     // to write it in case something goes horribly wrong, since it makes it
     // far easier to back out of this.
     $this->content = $content;
     $this->getProxyComment()->setContent($content);
     return $this;
   }
 
   private function getProxyComment() {
     if (!$this->proxyComment) {
       $this->proxyComment = new DifferentialTransactionComment();
     }
     return $this->proxyComment;
   }
 
   public function setProxyComment(DifferentialTransactionComment $proxy) {
     if ($this->proxyComment) {
       throw new Exception(pht('You can not overwrite a proxy comment.'));
     }
     $this->proxyComment = $proxy;
     return $this;
   }
 
   public function setRevision(DifferentialRevision $revision) {
     $this->getProxyComment()->setRevisionPHID($revision->getPHID());
     return $this->setRevisionID($revision->getID());
   }
 
   public function giveFacebookSomeArbitraryDiff(DifferentialDiff $diff) {
     $this->arbitraryDiffForFacebook = $diff;
     return $this;
   }
 
   public function getRequiredHandlePHIDs() {
     $phids = array();
 
     $metadata = $this->getMetadata();
     $added_reviewers = idx(
       $metadata,
       self::METADATA_ADDED_REVIEWERS);
     if ($added_reviewers) {
       foreach ($added_reviewers as $phid) {
         $phids[] = $phid;
       }
     }
     $added_ccs = idx(
       $metadata,
       self::METADATA_ADDED_CCS);
     if ($added_ccs) {
       foreach ($added_ccs as $phid) {
         $phids[] = $phid;
       }
     }
 
     return $phids;
   }
 
   public function getConfiguration() {
     return array(
       self::CONFIG_SERIALIZATION => array(
         'metadata' => self::SERIALIZATION_JSON,
       ),
     ) + parent::getConfiguration();
   }
 
   public function setContentSource(PhabricatorContentSource $content_source) {
     $this->contentSource = $content_source->serialize();
     return $this;
   }
 
   public function getContentSource() {
     return PhabricatorContentSource::newFromSerialized($this->contentSource);
   }
 
   public function getMarkupFieldKey($field) {
     return 'DC:'.$this->getID();
   }
 
   public function newMarkupEngine($field) {
     return PhabricatorMarkupEngine::newDifferentialMarkupEngine(
       array(
         'differential.diff' => $this->arbitraryDiffForFacebook,
       ));
   }
 
   public function getMarkupText($field) {
     return $this->getContent();
   }
 
   public function didMarkupText($field, $output, PhutilMarkupEngine $engine) {
     return $output;
   }
 
   public function shouldUseMarkupCache($field) {
     return (bool)$this->getID();
   }
 
   public function save() {
     $this->openTransaction();
       $result = parent::save();
 
       if ($this->getContent() !== null) {
         $content_source = PhabricatorContentSource::newForSource(
           PhabricatorContentSource::SOURCE_LEGACY,
           array());
 
         $xaction_phid = PhabricatorPHID::generateNewPHID(
           PhabricatorApplicationTransactionPHIDTypeTransaction::TYPECONST,
           DifferentialPHIDTypeRevision::TYPECONST);
 
         $proxy = $this->getProxyComment();
         $proxy
           ->setAuthorPHID($this->getAuthorPHID())
           ->setViewPolicy('public')
           ->setEditPolicy($this->getAuthorPHID())
           ->setContentSource($content_source)
           ->setCommentVersion(1)
           ->setLegacyCommentID($this->getID())
           ->setTransactionPHID($xaction_phid)
           ->save();
       }
 
     $this->saveTransaction();
 
     return $result;
   }
 
 }