diff --git a/train.h b/train.h
--- a/train.h
+++ b/train.h
@@ -217,6 +217,7 @@ static inline Vehicle *GetNextVehicle(co
 
 void ConvertOldMultiheadToNew(void);
 void ConnectMultiheadedTrains(void);
+uint CountArticulatedParts(EngineID engine_type);
 
 int CheckTrainInDepot(const Vehicle *v, bool needs_to_be_stopped);
 void CcCloneTrain(bool success, TileIndex tile, uint32 p1, uint32 p2);