diff --git a/src/workflow/ArcanistBrowseWorkflow.php b/src/workflow/ArcanistBrowseWorkflow.php
--- a/src/workflow/ArcanistBrowseWorkflow.php
+++ b/src/workflow/ArcanistBrowseWorkflow.php
@@ -225,6 +225,7 @@
     }
 
     $branch = $this->getArgument('branch', 'master');
+    $branch = phutil_escape_uri_path_component($branch);
 
     return $repo_uri.'browse/'.$branch.'/';
   }