diff --git a/lib/galaxy/tools/actions/metadata.py b/lib/galaxy/tools/actions/metadata.py
index 60b69be92c35..34cbcce9c7b8 100644
--- a/lib/galaxy/tools/actions/metadata.py
+++ b/lib/galaxy/tools/actions/metadata.py
@@ -88,7 +88,7 @@ def execute_via_app(self, tool, app, session_id, history_id, user=None,
                                                                      job_metadata=None,
                                                                      include_command=False,
                                                                      max_metadata_value_size=app.config.max_metadata_value_size,
-                                                                     kwds={'overwrite' : overwrite})
+                                                                     kwds={'overwrite': overwrite})
         incoming['__SET_EXTERNAL_METADATA_COMMAND_LINE__'] = cmd_line
         for name, value in tool.params_to_strings(incoming, app).items():
             job.add_parameter(name, value)