diff --git a/src/ai/backend/manager/models/session.py b/src/ai/backend/manager/models/session.py
index b8cf91be58..b509a996d0 100644
--- a/src/ai/backend/manager/models/session.py
+++ b/src/ai/backend/manager/models/session.py
@@ -1309,7 +1309,7 @@ async def _get_and_transit(
             transited = session_row.determine_and_set_status(status_changed_at=now)
 
             def _calculate_session_occupied_slots(session_row: SessionRow):
-                session_occupying_slots = ResourceSlot.from_json({**session_row.occupying_slots})
+                session_occupying_slots = ResourceSlot()
                 for row in session_row.kernels:
                     kernel_row = cast(KernelRow, row)
                     kernel_allocs = kernel_row.occupied_slots