diff --git a/src/applications/diffusion/query/history/DiffusionMercurialHistoryQuery.php b/src/applications/diffusion/query/history/DiffusionMercurialHistoryQuery.php
index 244c54f0a1..a72c15192e 100644
--- a/src/applications/diffusion/query/history/DiffusionMercurialHistoryQuery.php
+++ b/src/applications/diffusion/query/history/DiffusionMercurialHistoryQuery.php
@@ -44,11 +44,11 @@ final class DiffusionMercurialHistoryQuery extends DiffusionHistoryQuery {
     }
 
     list($stdout) = $repository->execxLocalCommand(
-      'log --debug --template %s --limit %d %C --rev %s::0 %C',
+      'log --debug --template %s --limit %d %C --rev %s %C',
       '{node};{parents}\\n',
       ($this->getOffset() + $this->getLimit()), // No '--skip' in Mercurial.
       $branch_arg,
-      $commit_hash,
+      hgsprintf('reverse(%s::%s)', '0', $commit_hash),
       $path_arg);
 
     $lines = explode("\n", trim($stdout));
diff --git a/src/applications/diffusion/query/lastmodified/DiffusionMercurialLastModifiedQuery.php b/src/applications/diffusion/query/lastmodified/DiffusionMercurialLastModifiedQuery.php
index 9a8e648e66..e0a40e76c7 100644
--- a/src/applications/diffusion/query/lastmodified/DiffusionMercurialLastModifiedQuery.php
+++ b/src/applications/diffusion/query/lastmodified/DiffusionMercurialLastModifiedQuery.php
@@ -10,9 +10,9 @@ final class DiffusionMercurialLastModifiedQuery
     $path = $drequest->getPath();
 
     list($hash) = $repository->execxLocalCommand(
-      'log --template %s --limit 1 --rev %s::0 -- %s',
+      'log --template %s --limit 1 --rev %s -- %s',
       '{node}',
-      $drequest->getCommit(),
+      hgsprintf('reverse(%s::%s)', '0', $drequest->getCommit()),
       nonempty(ltrim($path, '/'), '.'));
 
     $commit = id(new PhabricatorRepositoryCommit())->loadOneWhere(