diff --git a/src/group.h b/src/group.h
--- a/src/group.h
+++ b/src/group.h
@@ -112,5 +112,6 @@ void SetTrainGroupID(Train *v, GroupID g
 void UpdateTrainGroupID(Train *v);
 void RemoveAllGroupsForCompany(const CompanyID company);
 bool GroupIsInGroup(GroupID search, GroupID group);
+void UpdateCompanyGroupLiveries(const Company *c);
 
 #endif /* GROUP_H */