diff --git a/src/app_controller.py b/src/app_controller.py
index 20081fe4..313238ba 100644
--- a/src/app_controller.py
+++ b/src/app_controller.py
@@ -2300,13 +2300,9 @@ class AppController:
            break
 
        if kind == 'response' and 'usage' in payload:
+        from src.openai_schemas import UsageStats as _US
         u = payload['usage']
-        u_stats = models.UsageStats(
-         input_tokens=u.get('input_tokens', 0) or 0,
-         output_tokens=u.get('output_tokens', 0) or 0,
-         cache_read_tokens=u.get('cache_read_input_tokens', 0) or 0,
-         cache_creation_tokens=u.get('cache_creation_input_tokens', 0) or 0,
-        )
+        u_stats = _US.from_dict(u)
         for k in ['input_tokens', 'output_tokens', 'cache_read_input_tokens', 'cache_creation_input_tokens', 'total_tokens']:
          if k in new_usage: new_usage[k] += u.get(k, 0) or 0
         tier = comms_entry.source_tier