diff --git a/src/newgrf_commons.cpp b/src/newgrf_commons.cpp
--- a/src/newgrf_commons.cpp
+++ b/src/newgrf_commons.cpp
@@ -146,7 +146,7 @@ uint16 OverrideManagerBase::AddEntityID(
  * @param entity_id ID of the entity being queried.
  * @return GRFID.
  */
-uint16 OverrideManagerBase::GetGRFID(uint16 entity_id) const
+uint32 OverrideManagerBase::GetGRFID(uint16 entity_id) const
 {
 	return mapping_ID[entity_id].grfid;
 }