diff --git a/src/repository/api/mercurial/ArcanistMercurialAPI.php b/src/repository/api/mercurial/ArcanistMercurialAPI.php
index fd893b42..4968a56d 100644
--- a/src/repository/api/mercurial/ArcanistMercurialAPI.php
+++ b/src/repository/api/mercurial/ArcanistMercurialAPI.php
@@ -33,10 +33,11 @@ class ArcanistMercurialAPI extends ArcanistRepositoryAPI {
 
   public function getSourceControlBaseRevision() {
     list($stdout) = execx(
-      '(cd %s && hg id -ir %s)',
+      '(cd %s && hg log -l 1 --template %s -r %s)',
       $this->getPath(),
+      '{node}\\n',
       $this->getRelativeCommit());
-    return $stdout;
+    return rtrim($stdout, "\n");
   }
 
   public function getSourceControlPath() {
diff --git a/src/workflow/patch/ArcanistPatchWorkflow.php b/src/workflow/patch/ArcanistPatchWorkflow.php
index eaaa100f..76cd249e 100644
--- a/src/workflow/patch/ArcanistPatchWorkflow.php
+++ b/src/workflow/patch/ArcanistPatchWorkflow.php
@@ -403,7 +403,7 @@ EOTEXT
       }
 
       return $patch_err;
-    } else {
+    } else if ($repository_api instanceof ArcanistGitAPI) {
       $future = new ExecFuture(
         '(cd %s; git apply --index --reject)',
         $repository_api->getPath());
@@ -412,6 +412,17 @@ EOTEXT
 
       echo phutil_console_format(
         "<bg:green>** OKAY **</bg> Successfully applied patch.\n");
+    } else if ($repository_api instanceof ArcanistMercurialAPI) {
+      $future = new ExecFuture(
+        '(cd %s; hg import --no-commit -)',
+        $repository_api->getPath());
+      $future->write($bundle->toGitPatch());
+      $future->resolvex();
+
+      echo phutil_console_format(
+        "<bg:green>** OKAY **</bg> Successfully applied patch.\n");
+    } else {
+      throw new Exception('Unknown version control system.');
     }
 
     return 0;