diff --git a/src/newgrf_engine.cpp b/src/newgrf_engine.cpp
--- a/src/newgrf_engine.cpp
+++ b/src/newgrf_engine.cpp
@@ -640,7 +640,8 @@ static uint32 VehicleGetVariable(Vehicle
 			if (!v->IsGroundVehicle() || parameter == 0x61) return 0;
 
 			/* Only allow callbacks that don't change properties to avoid circular dependencies. */
-			if (object->callback == CBID_NO_CALLBACK || object->callback == CBID_TRAIN_ALLOW_WAGON_ATTACH || object->callback == CBID_VEHICLE_START_STOP_CHECK || object->callback == CBID_VEHICLE_32DAY_CALLBACK) {
+			if (object->callback == CBID_NO_CALLBACK || object->callback == CBID_RANDOM_TRIGGER || object->callback == CBID_TRAIN_ALLOW_WAGON_ATTACH ||
+					object->callback == CBID_VEHICLE_START_STOP_CHECK || object->callback == CBID_VEHICLE_32DAY_CALLBACK || object->callback == CBID_VEHICLE_COLOUR_MAPPING) {
 				Vehicle *u = v->Move((int32)GetRegister(0x10F));
 				if (u == NULL) return 0;