diff --git a/api/code/metroplanner_api/v1/endpoints/_planstates.py b/api/code/metroplanner_api/v1/endpoints/_planstates.py
index 65e133f..b516a73 100644
--- a/api/code/metroplanner_api/v1/endpoints/_planstates.py
+++ b/api/code/metroplanner_api/v1/endpoints/_planstates.py
@@ -45,7 +45,7 @@ def post_planstate(
             set_planstate_data["created_at"] = (now := datetime.now().isoformat())
 
             created_result = db.planstates.insert_one(
-                {set_planstate_data}
+                set_planstate_data
                 | {
                     "lines": planstate_data.lines,
                     "nodes": planstate_data.nodes,