diff --git a/users/ignoring.rst b/users/ignoring.rst
index 46e28dc84..e2c51431f 100644
--- a/users/ignoring.rst
+++ b/users/ignoring.rst
@@ -62,7 +62,7 @@ The ``.stignore`` file contains a list of file or path patterns. The
    ``(?i)`` prefix can be combined with other patterns, for example the
    pattern ``(?i)!picture*.png`` indicates that ``Picture1.PNG`` should
    be synchronized. Note that case-insensitive patterns must start with
-   ``(?i)`` when combined with other flags.
+   ``(?i)`` when combined with other flags. On Mac OS and Windows, patterns are always case-insensitive.
 
 -  A line beginning with ``//`` is a comment and has no effect.