diff --git a/src/ext/java/org/opentripplanner/ext/siri/SiriTimetableSnapshotSource.java b/src/ext/java/org/opentripplanner/ext/siri/SiriTimetableSnapshotSource.java
index 6d94f261173..7d7cd0e5443 100644
--- a/src/ext/java/org/opentripplanner/ext/siri/SiriTimetableSnapshotSource.java
+++ b/src/ext/java/org/opentripplanner/ext/siri/SiriTimetableSnapshotSource.java
@@ -10,7 +10,6 @@
 import static org.opentripplanner.model.UpdateError.UpdateErrorType.NO_START_DATE;
 import static org.opentripplanner.model.UpdateError.UpdateErrorType.NO_UPDATES;
 import static org.opentripplanner.model.UpdateError.UpdateErrorType.TRIP_NOT_FOUND_IN_PATTERN;
-import static org.opentripplanner.model.UpdateError.UpdateErrorType.UNKNOWN;
 
 import com.google.common.base.Preconditions;
 import java.time.LocalDate;
@@ -890,7 +889,7 @@ private List<UpdateError> handleModifiedTrip(
 
       if (exactPattern != null) {
         Timetable currentTimetable = getCurrentTimetable(exactPattern, serviceDate);
-        TripTimes exactUpdatedTripTimes = createUpdatedTripTimes(
+        var updateResult = createUpdatedTripTimes(
           currentTimetable,
           estimatedVehicleJourney,
           tripMatchedByServiceJourneyId.getId(),
@@ -898,15 +897,15 @@ private List<UpdateError> handleModifiedTrip(
           timeZone,
           transitModel.getDeduplicator()
         );
-        if (exactUpdatedTripTimes != null) {
-          times.add(exactUpdatedTripTimes);
+        if (updateResult.isSuccess()) {
+          times.add(updateResult.successValue());
           patterns.add(exactPattern);
         } else {
           LOG.info(
             "Failed to update TripTimes for trip found by exact match {}",
             tripMatchedByServiceJourneyId.getId()
           );
-          return List.of(new UpdateError(tripMatchedByServiceJourneyId.getId(), UNKNOWN));
+          return List.of(updateResult.failureValue());
         }
       }
     } else {
@@ -942,7 +941,7 @@ private List<UpdateError> handleModifiedTrip(
         TripPattern pattern = getPatternForTrip(matchingTrip, estimatedVehicleJourney);
         if (pattern != null) {
           Timetable currentTimetable = getCurrentTimetable(pattern, serviceDate);
-          TripTimes updatedTripTimes = createUpdatedTripTimes(
+          var updateResult = createUpdatedTripTimes(
             currentTimetable,
             estimatedVehicleJourney,
             matchingTrip.getId(),
@@ -950,10 +949,10 @@ private List<UpdateError> handleModifiedTrip(
             timeZone,
             transitModel.getDeduplicator()
           );
-          if (updatedTripTimes != null) {
+          updateResult.ifSuccess(tripTimes -> {
             patterns.add(pattern);
-            times.add(updatedTripTimes);
-          }
+            times.add(tripTimes);
+          });
         }
       }
     }
diff --git a/src/ext/java/org/opentripplanner/ext/siri/TimetableHelper.java b/src/ext/java/org/opentripplanner/ext/siri/TimetableHelper.java
index 2d6a5a495fb..8a7f39fdd3a 100644
--- a/src/ext/java/org/opentripplanner/ext/siri/TimetableHelper.java
+++ b/src/ext/java/org/opentripplanner/ext/siri/TimetableHelper.java
@@ -5,6 +5,7 @@
 import static org.opentripplanner.model.PickDrop.SCHEDULED;
 import static org.opentripplanner.model.UpdateError.UpdateErrorType.INVALID_INPUT_STRUCTURE;
 import static org.opentripplanner.model.UpdateError.UpdateErrorType.NON_INCREASING_TRIP_TIMES;
+import static org.opentripplanner.model.UpdateError.UpdateErrorType.TOO_FEW_STOPS;
 import static org.opentripplanner.model.UpdateError.UpdateErrorType.TRIP_NOT_FOUND_IN_PATTERN;
 import static org.opentripplanner.model.UpdateError.UpdateErrorType.UNKNOWN;
 
@@ -63,7 +64,7 @@ public class TimetableHelper {
    * @return new copy of updated TripTimes after TripUpdate has been applied on TripTimes of trip
    * with the id specified in the trip descriptor of the TripUpdate; null if something went wrong
    */
-  public static TripTimes createUpdatedTripTimes(
+  public static Result<TripTimes, UpdateError> createUpdatedTripTimes(
     Timetable timetable,
     EstimatedVehicleJourney journey,
     FeedScopedId tripId,
@@ -78,14 +79,14 @@ public static TripTimes createUpdatedTripTimes(
     final TripTimes existingTripTimes = timetable.getTripTimes(tripId);
     if (existingTripTimes == null) {
       LOG.debug("tripId {} not found in pattern.", tripId);
-      return null;
+      return UpdateError.result(tripId, TRIP_NOT_FOUND_IN_PATTERN);
     }
 
     TripTimes oldTimes = new TripTimes(existingTripTimes);
 
     if (journey.isCancellation() != null && journey.isCancellation()) {
       oldTimes.cancelTrip();
-      return oldTimes;
+      return Result.success(oldTimes);
     }
 
     List<EstimatedCall> estimatedCalls = getEstimatedCalls(journey);
@@ -109,7 +110,7 @@ public static TripTimes createUpdatedTripTimes(
       getStopById
     );
     if (modifiedStopTimes == null) {
-      return null;
+      return UpdateError.result(tripId, UNKNOWN);
     }
     TripTimes newTimes = new TripTimes(oldTimes.getTrip(), modifiedStopTimes, deduplicator);
 
@@ -387,15 +388,15 @@ public static TripTimes createUpdatedTripTimes(
         tripId,
         invalidStopIndex.getAsInt()
       );
-      return null;
+      return UpdateError.result(tripId, NON_INCREASING_TRIP_TIMES);
     }
 
     if (newTimes.getNumStops() != pattern.numberOfStops()) {
-      return null;
+      return UpdateError.result(tripId, TOO_FEW_STOPS);
     }
 
     LOG.debug("A valid TripUpdate object was applied using the Timetable class update method.");
-    return newTimes;
+    return Result.success(newTimes);
   }
 
   private static int calculateDayOffset(TripTimes oldTimes) {