diff --git a/WarmlyShip/WarmlyShip/AbstractMap.cs b/WarmlyShip/WarmlyShip/AbstractMap.cs
index 21023c3..b05b4fd 100644
--- a/WarmlyShip/WarmlyShip/AbstractMap.cs
+++ b/WarmlyShip/WarmlyShip/AbstractMap.cs
@@ -38,7 +38,7 @@ namespace WarmlyShip
 			{
 				for (int j = (int)(position.Left / _size_x); j <= (int)(position.Right / _size_x); ++j)
 				{
-					if (i >= 0 && j >= 0 && _map[i, j] == _barrier) return false;
+					if (i >= 0 && j >= 0 && i < _map.GetLength(0) && j < _map.GetLength(1) && _map[i, j] == _barrier) return false;
 				}
 			}
 			return true;