diff --git a/GameMap.py b/GameMap.py
index e35d8c6..4c7f9ce 100644
--- a/GameMap.py
+++ b/GameMap.py
@@ -28,7 +28,7 @@ class GameMap:
                 errorMessage = "The mark is already busy by the player '" + str(self.data[(x, y)].get_name()) + "'"
                 raise KeyError(errorMessage)
         else:
-            errorMessage = "The mark" + str((x,y)) + " is beyond preset max values, max_x - " + str(self.max_size_x) + ", max_y - " + str(self.max_size_y)
+            errorMessage = "The mark" + str((x,y)) + " is beyond preset max values or 0, max_x - " + str(self.max_size_x) + ", max_y - " + str(self.max_size_y)
             raise IndexError(errorMessage)