diff --git a/src/newgrf.cpp b/src/newgrf.cpp
index 043b6f2fa9..bc4ec68779 100644
--- a/src/newgrf.cpp
+++ b/src/newgrf.cpp
@@ -4298,12 +4298,13 @@ static ChangeInfoResult ObjectChangeInfo(uint id, int numinfo, int prop, const G
 
 			case A0RPI_OBJECT_USE_LAND_GROUND:
 				if (MappedPropertyLengthMismatch(buf, 1, mapping_entry)) break;
-				SB(spec->ctrl_flags, OBJECT_CTRL_FLAG_USE_LAND_GROUND, 1, (buf->ReadByte() != 0 ? 1 : 0));
+				spec->ctrl_flags &= ~OBJECT_CTRL_FLAG_USE_LAND_GROUND;
+				if (buf->ReadByte() != 0) spec->ctrl_flags |= OBJECT_CTRL_FLAG_USE_LAND_GROUND;
 				break;
 
 			case A0RPI_OBJECT_EDGE_FOUNDATION_MODE:
 				if (MappedPropertyLengthMismatch(buf, 4, mapping_entry)) break;
-				SetBit(spec->ctrl_flags, OBJECT_CTRL_FLAG_EDGE_FOUNDATION);
+				spec->ctrl_flags |= OBJECT_CTRL_FLAG_EDGE_FOUNDATION;
 				for (int i = 0; i < 4; i++) {
 					spec->edge_foundation[i] = buf->ReadByte();
 				}
@@ -4311,7 +4312,8 @@ static ChangeInfoResult ObjectChangeInfo(uint id, int numinfo, int prop, const G
 
 			case A0RPI_OBJECT_FLOOD_RESISTANT:
 				if (MappedPropertyLengthMismatch(buf, 1, mapping_entry)) break;
-				SB(spec->ctrl_flags, OBJECT_CTRL_FLAG_FLOOD_RESISTANT, 1, (buf->ReadByte() != 0 ? 1 : 0));
+				spec->ctrl_flags &= ~OBJECT_CTRL_FLAG_FLOOD_RESISTANT;
+				if (buf->ReadByte() != 0) spec->ctrl_flags |= OBJECT_CTRL_FLAG_FLOOD_RESISTANT;
 				break;
 
 			default:
diff --git a/src/newgrf_object.h b/src/newgrf_object.h
index 0288466b87..d31e4c35b8 100644
--- a/src/newgrf_object.h
+++ b/src/newgrf_object.h
@@ -43,8 +43,8 @@ DECLARE_ENUM_AS_BIT_SET(ObjectFlags)
 enum ObjectCtrlFlags {
 	OBJECT_CTRL_FLAG_NONE               =       0, ///< Just nothing.
 	OBJECT_CTRL_FLAG_USE_LAND_GROUND    = 1 <<  0, ///< Use land for ground sprite.
-	OBJECT_CTRL_FLAG_EDGE_FOUNDATION    = 1 <<  2, ///< Use edge foundation mode.
-	OBJECT_CTRL_FLAG_FLOOD_RESISTANT    = 1 <<  3, ///< Object is flood-resistant.
+	OBJECT_CTRL_FLAG_EDGE_FOUNDATION    = 1 <<  1, ///< Use edge foundation mode.
+	OBJECT_CTRL_FLAG_FLOOD_RESISTANT    = 1 <<  2, ///< Object is flood-resistant.
 };
 DECLARE_ENUM_AS_BIT_SET(ObjectCtrlFlags)