diff --git a/lib/file_store/local_store.rb b/lib/file_store/local_store.rb
index fc24c767bd5..ef36b37f7e0 100644
--- a/lib/file_store/local_store.rb
+++ b/lib/file_store/local_store.rb
@@ -33,7 +33,7 @@ module FileStore
     end
 
     def relative_base_url
-      "#{Discourse.base_uri}#{upload_path}"
+      File.join(Discourse.base_uri, upload_path)
     end
 
     def external?