diff --git a/sunfish.py b/sunfish.py
old mode 100755
new mode 100644
index 0c43388..a3c9367
--- a/sunfish.py
+++ b/sunfish.py
@@ -299,7 +299,7 @@ def bound(self, pos, gamma, depth, can_null=True):
 
         # Let's not repeat positions. We don't chat
         # - at the root (can_null=False) since it is in history, but not a draw.
-        # - at depth=0, since it would be expensive and break "futulity pruning".
+        # - at depth=0, since it would be expensive and break "futility pruning".
         if can_null and depth > 0 and pos in self.history:
             return 0