diff --git a/src/applications/diffusion/query/rawdiff/DiffusionGitRawDiffQuery.php b/src/applications/diffusion/query/rawdiff/DiffusionGitRawDiffQuery.php
index 5983b2723e..9c894437ef 100644
--- a/src/applications/diffusion/query/rawdiff/DiffusionGitRawDiffQuery.php
+++ b/src/applications/diffusion/query/rawdiff/DiffusionGitRawDiffQuery.php
@@ -1,50 +1,50 @@
 <?php
 
 final class DiffusionGitRawDiffQuery extends DiffusionRawDiffQuery {
 
   protected function newQueryFuture() {
     $drequest = $this->getRequest();
     $repository = $drequest->getRepository();
 
     $commit = $this->getAnchorCommit();
 
     $options = array(
       '-M',
       '-C',
       '--no-ext-diff',
       '--no-color',
       '--src-prefix=a/',
       '--dst-prefix=b/',
       '-U'.(int)$this->getLinesOfContext(),
     );
 
     $against = $this->getAgainstCommit();
     if ($against === null) {
       // Check if this is the root commit by seeing if it has parents, since
       // `git diff X^ X` does not work if "X" is the initial commit.
       list($parents) = $repository->execxLocalCommand(
-        'log -n 1 %s --',
+        'log -n 1 %s %s --',
         '--format=%P',
         gitsprintf('%s', $commit));
 
       if (strlen(trim($parents))) {
         $against = $commit.'^';
       } else {
         $against = ArcanistGitAPI::GIT_MAGIC_ROOT_COMMIT;
       }
     }
 
     $path = $drequest->getPath();
     if (!strlen($path)) {
       $path = '.';
     }
 
     return $repository->getLocalCommandFuture(
       'diff %Ls %s %s -- %s',
       $options,
       gitsprintf('%s', $against),
       gitsprintf('%s', $commit),
       $path);
   }
 
 }