diff --git a/backend/src/lib/workforce.js b/backend/src/lib/workforce.js
index 28a87c2..58028d2 100644
--- a/backend/src/lib/workforce.js
+++ b/backend/src/lib/workforce.js
@@ -94,10 +94,9 @@ function weeklyFetchDates(from, to) {
 }
 
 // Fetch timesheets for a single date — no location param (mirrors PBI pattern).
-// Returns the weekly timesheet record(s) containing this date.
-// Each record: { id, user_id, shifts: [{ department_id, date, cost, leave_request_id, ... }] }
+// include_oncosts=true is required to get cost_with_oncosts on nested shifts[].
 async function fetchTimesheetsForDate(dateStr) {
-  try { return await wfFetchPaged(`/api/v2/timesheets/on/${dateStr}?show_costs=true`) }
+  try { return await wfFetchPaged(`/api/v2/timesheets/on/${dateStr}?show_costs=true&include_oncosts=true`) }
   catch { return [] }
 }