diff --git a/www/js/diary/timelineHelper.ts b/www/js/diary/timelineHelper.ts
index 59bc6e964..595fadf48 100644
--- a/www/js/diary/timelineHelper.ts
+++ b/www/js/diary/timelineHelper.ts
@@ -11,6 +11,7 @@ import {
   TimelineEntry,
   GeoJSONData,
   UnprocessedTrip,
+  FilteredLocation,
 } from '../types/diaryTypes';
 import { getLabelInputDetails, getLabelInputs } from '../survey/multilabel/confirmHelper';
 import { LabelOptions } from '../types/labelTypes';
@@ -338,8 +339,7 @@ const transitionTrip2TripObj = function (trip) {
   );
   const getSensorData = window['cordova'].plugins.BEMUserCache.getSensorDataForInterval;
   return getUnifiedDataForInterval('background/filtered_location', tq, getSensorData).then(
-    function (locationList: Array<any>) {
-      // change 'any' later
+    function (locationList: Array<ServerData<FilteredLocation>>) {
       if (locationList.length == 0) {
         return undefined;
       }
@@ -527,7 +527,7 @@ export const readUnprocessedTrips = function (startTs, endTs, lastProcessedTrip)
         logDebug(JSON.stringify(trip, null, 2));
       });
       var tripFillPromises = tripsList.map(transitionTrip2TripObj);
-      return Promise.all(tripFillPromises).then(function (raw_trip_gj_list) {
+      return Promise.all(tripFillPromises).then(function (raw_trip_gj_list: UnprocessedTrip[]) {
         // Now we need to link up the trips. linking unprocessed trips
         // to one another is fairly simple, but we need to link the
         // first unprocessed trip to the last processed trip.
@@ -540,7 +540,7 @@ export const readUnprocessedTrips = function (startTs, endTs, lastProcessedTrip)
         logDebug(`mapped trips to trip_gj_list of size ${raw_trip_gj_list.length}`);
         /* Filtering: we will keep trips that are 1) defined and 2) have a distance >= 100m or duration >= 5 minutes
               https://github.com/e-mission/e-mission-docs/issues/966#issuecomment-1709112578 */
-        const trip_gj_list: UnprocessedTrip[] = raw_trip_gj_list.filter(
+        const trip_gj_list = raw_trip_gj_list.filter(
           (trip) => trip && (trip.distance >= 100 || trip.duration >= 300),
         );
         logDebug(
diff --git a/www/js/types/diaryTypes.ts b/www/js/types/diaryTypes.ts
index 534f1dfdc..5fa81298d 100644
--- a/www/js/types/diaryTypes.ts
+++ b/www/js/types/diaryTypes.ts
@@ -191,6 +191,22 @@ export type SectionData = {
   distance: number;
 };
 
+// used in timelineHelper's `transitionTrip2TripObj`
+export type FilteredLocation = {
+  accuracy: number;
+  altitude: number;
+  elapsedRealtimeNanos: number;
+  filter: number;
+  fmt_time: string;
+  heading: number;
+  latitude: number;
+  loc: Geometry;
+  local_dt: LocalDt;
+  longitude: number;
+  sensed_speed: number;
+  ts: number;
+};
+
 export type GeoJSONStyledFeature = Feature & { style?: { color: string } };
 
 export type GeoJSONData = {