1 files changed, 4 insertions, 0 deletions
diff --git a/ship_cmd.c b/ship_cmd.c
index c7330b9d2..c85377187 100644
--- a/ship_cmd.c
+++ b/ship_cmd.c
@@ -841,6 +841,10 @@ int32 CmdBuildShip(int x, int y, uint32 flags, uint32 p1, uint32 p2)
 
 	if (!IsEngineBuildable(p1, VEH_Ship)) return CMD_ERROR;
 
+	if (!IsShipDepotTile((TileIndex)tile)) return CMD_ERROR;
+
+	if (_map_owner[tile] != _current_player) return CMD_ERROR;
+
 	SET_EXPENSES_TYPE(EXPENSES_NEW_VEHICLES);
 
 	value = EstimateShipCost(p1);