diff --git a/packages/api/src/router/timeline-project-context-response-support.ts b/packages/api/src/router/timeline-project-context-response-support.ts
index 7553a9e..4fcf138 100644
--- a/packages/api/src/router/timeline-project-context-response-support.ts
+++ b/packages/api/src/router/timeline-project-context-response-support.ts
@@ -4,7 +4,6 @@ import {
   summarizeTimelineEntries,
 } from "./timeline-read-shared.js";
 import {
-  formatHolidayOverlays,
   summarizeHolidayOverlays,
 } from "./timeline-holiday-read.js";
 
@@ -17,7 +16,7 @@ export function buildTimelineProjectContextSummary(input: {
   resourceIds: string[];
   allResourceAllocations: unknown[];
   assignmentConflicts: Array<{ crossProjectOverlapCount: number }>;
-  holidayOverlays: ReturnType<typeof formatHolidayOverlays>;
+  holidayOverlays: Parameters<typeof summarizeHolidayOverlays>[0];
 }) {
   return {
     ...summarizeTimelineEntries({
@@ -89,7 +88,7 @@ export function buildTimelineProjectContextDetailResponse<
   allResourceAllocations: TBooking[];
   resourceIds: string[];
   assignmentConflicts: TConflict[];
-  holidayOverlays: ReturnType<typeof formatHolidayOverlays>;
+  holidayOverlays: Parameters<typeof summarizeHolidayOverlays>[0];
   directory: TimelineAnonymizationDirectory;
 }) {
   const base = buildTimelineProjectContextResponse({