diff --git a/src/applications/repository/management/PhabricatorRepositoryManagementParentsWorkflow.php b/src/applications/repository/management/PhabricatorRepositoryManagementParentsWorkflow.php
index 61c5fedf96..671287c3d6 100644
--- a/src/applications/repository/management/PhabricatorRepositoryManagementParentsWorkflow.php
+++ b/src/applications/repository/management/PhabricatorRepositoryManagementParentsWorkflow.php
@@ -1,180 +1,181 @@
 <?php
 
 final class PhabricatorRepositoryManagementParentsWorkflow
   extends PhabricatorRepositoryManagementWorkflow {
 
   protected function didConstruct() {
     $this
       ->setName('parents')
       ->setExamples('**parents** [options] [__repository__] ...')
       ->setSynopsis(
         pht(
           'Build parent caches in repositories that are missing the data, '.
           'or rebuild them in a specific __repository__.'))
       ->setArguments(
         array(
           array(
             'name'        => 'repos',
             'wildcard'    => true,
           ),
         ));
   }
 
   public function execute(PhutilArgumentParser $args) {
     $repos = $this->loadRepositories($args, 'repos');
     if (!$repos) {
       $repos = id(new PhabricatorRepositoryQuery())
         ->setViewer($this->getViewer())
         ->execute();
     }
 
     $console = PhutilConsole::getConsole();
     foreach ($repos as $repo) {
       $monogram = $repo->getMonogram();
       if ($repo->isSVN()) {
         $console->writeOut(
           "%s\n",
           pht(
             'Skipping "%s": Subversion repositories do not require this '.
             'cache to be built.',
             $monogram));
         continue;
       }
       $this->rebuildRepository($repo);
     }
 
     return 0;
   }
 
   private function rebuildRepository(PhabricatorRepository $repo) {
     $console = PhutilConsole::getConsole();
     $console->writeOut("%s\n", pht('Rebuilding "%s"...', $repo->getMonogram()));
 
     $refs = id(new PhabricatorRepositoryRefCursorQuery())
       ->setViewer($this->getViewer())
       ->withRefTypes(array(PhabricatorRepositoryRefCursor::TYPE_BRANCH))
       ->withRepositoryPHIDs(array($repo->getPHID()))
+      ->needPositions(true)
       ->execute();
 
     $graph = array();
     foreach ($refs as $ref) {
       if (!$repo->shouldTrackBranch($ref->getRefName())) {
         continue;
       }
 
       $console->writeOut(
         "%s\n",
         pht('Rebuilding branch "%s"...', $ref->getRefName()));
 
-      $commit = $ref->getCommitIdentifier();
-
-      if ($repo->isGit()) {
-        $stream = new PhabricatorGitGraphStream($repo, $commit);
-      } else {
-        $stream = new PhabricatorMercurialGraphStream($repo, $commit);
-      }
-
-      $discover = array($commit);
-      while ($discover) {
-        $target = array_pop($discover);
-        if (isset($graph[$target])) {
-          continue;
+      foreach ($ref->getPositionIdentifiers() as $commit) {
+        if ($repo->isGit()) {
+          $stream = new PhabricatorGitGraphStream($repo, $commit);
+        } else {
+          $stream = new PhabricatorMercurialGraphStream($repo, $commit);
         }
-        $graph[$target] = $stream->getParents($target);
-        foreach ($graph[$target] as $parent) {
-          $discover[] = $parent;
+
+        $discover = array($commit);
+        while ($discover) {
+          $target = array_pop($discover);
+          if (isset($graph[$target])) {
+            continue;
+          }
+          $graph[$target] = $stream->getParents($target);
+          foreach ($graph[$target] as $parent) {
+            $discover[] = $parent;
+          }
         }
       }
     }
 
     $console->writeOut(
       "%s\n",
       pht(
         'Found %s total commit(s); updating...',
         phutil_count($graph)));
 
     $commit_table = id(new PhabricatorRepositoryCommit());
     $commit_table_name = $commit_table->getTableName();
     $conn_w = $commit_table->establishConnection('w');
 
     $bar = id(new PhutilConsoleProgressBar())
       ->setTotal(count($graph));
 
     $need = array();
     foreach ($graph as $child => $parents) {
       foreach ($parents as $parent) {
         $need[$parent] = $parent;
       }
       $need[$child] = $child;
     }
 
     $map = array();
     foreach (array_chunk($need, 2048) as $chunk) {
       $rows = queryfx_all(
         $conn_w,
         'SELECT id, commitIdentifier FROM %T
           WHERE commitIdentifier IN (%Ls) AND repositoryID = %d',
         $commit_table_name,
         $chunk,
         $repo->getID());
       foreach ($rows as $row) {
         $map[$row['commitIdentifier']] = $row['id'];
       }
     }
 
     $insert_sql = array();
     $delete_sql = array();
 
     foreach ($graph as $child => $parents) {
       $names = $parents;
       $names[] = $child;
 
       foreach ($names as $name) {
         if (empty($map[$name])) {
           throw new Exception(pht('Unknown commit "%s"!', $name));
         }
       }
 
       if (!$parents) {
         // Write an explicit 0 to indicate "no parents" instead of "no data".
         $insert_sql[] = qsprintf(
           $conn_w,
           '(%d, 0)',
           $map[$child]);
       } else {
         foreach ($parents as $parent) {
           $insert_sql[] = qsprintf(
             $conn_w,
             '(%d, %d)',
             $map[$child],
             $map[$parent]);
         }
       }
 
       $delete_sql[] = $map[$child];
 
       $bar->update(1);
     }
 
     $commit_table->openTransaction();
     foreach (PhabricatorLiskDAO::chunkSQL($delete_sql) as $chunk) {
       queryfx(
         $conn_w,
         'DELETE FROM %T WHERE childCommitID IN (%Q)',
         PhabricatorRepository::TABLE_PARENTS,
         $chunk);
     }
 
     foreach (PhabricatorLiskDAO::chunkSQL($insert_sql) as $chunk) {
       queryfx(
         $conn_w,
         'INSERT INTO %T (childCommitID, parentCommitID) VALUES %Q',
         PhabricatorRepository::TABLE_PARENTS,
         $chunk);
     }
     $commit_table->saveTransaction();
 
     $bar->done();
   }
 
 }