diff --git a/contribs/drt/src/main/java/org/matsim/contrib/drt/prebooking/PrebookingStopActivity.java b/contribs/drt/src/main/java/org/matsim/contrib/drt/prebooking/PrebookingStopActivity.java
index 3c04ba985a3..e55af9e76a5 100644
--- a/contribs/drt/src/main/java/org/matsim/contrib/drt/prebooking/PrebookingStopActivity.java
+++ b/contribs/drt/src/main/java/org/matsim/contrib/drt/prebooking/PrebookingStopActivity.java
@@ -206,8 +206,10 @@ protected void simStep(double now) {
 	@Override
 	public void notifyPassengersAreReadyForDeparture(List<MobsimPassengerAgent> passengers, double now) {
 		var request = getRequestForPassengers(passengers.stream().map(Identifiable::getId).toList());
-		queuePickup(request, now);
-		expectedPickups.remove(request.getId());
+		if(expectedPickups.containsKey(request.getId())) {
+			queuePickup(request, now);
+			expectedPickups.remove(request.getId());
+		}
 	}
 
 	private AcceptedDrtRequest getRequestForPassengers(List<Id<Person>> passengerIds) {