[ 1243081 ] repair typos
diff --git a/Lib/plat-mac/macostools.py b/Lib/plat-mac/macostools.py
index 06bc92f..f7ce468 100644
--- a/Lib/plat-mac/macostools.py
+++ b/Lib/plat-mac/macostools.py
@@ -13,7 +13,7 @@
 try:
     openrf = MacOS.openrf
 except AttributeError:
-    # Backward compatability
+    # Backward compatibility
     openrf = open
 
 Error = 'macostools.Error'