diff --git a/Doc/using/cmdline.rst b/Doc/using/cmdline.rst
index 9274d8e..c386fb4 100644
--- a/Doc/using/cmdline.rst
+++ b/Doc/using/cmdline.rst
@@ -448,7 +448,7 @@
 .. envvar:: PYTHONCASEOK
 
    If this is set, Python ignores case in :keyword:`import` statements.  This
-   only works on Windows.
+   only works on Windows, OS X, and OS/2.
 
 
 .. envvar:: PYTHONDONTWRITEBYTECODE