diff --git a/battleship/utils.py b/battleship/utils.py
index 6f76c1f..4758de5 100644
--- a/battleship/utils.py
+++ b/battleship/utils.py
@@ -144,6 +144,6 @@ def kill_field(field):
                 if killed:
                     for x, y in ship:
                         cells[x][y] = 'x'
-                    for x, y in find_borders(ship[0][0], ship[0][1], len(ship), not bool(ship[-1][1] - ship[0][1])):
+                    for x, y in find_borders(ship[0][0], ship[0][1], len(ship), bool(ship[-1][1] - ship[0][1])):
                         cells[x][y] = '.'
     return ''.join([''.join(arr) for arr in cells])