diff --git a/reference/filesystem/functions/dirname.xml b/reference/filesystem/functions/dirname.xml
index 3815335260..50f0fd23f7 100644
--- a/reference/filesystem/functions/dirname.xml
+++ b/reference/filesystem/functions/dirname.xml
@@ -115,6 +115,13 @@ echo "3) ".dirname(".");
     as "<literal>..</literal>".
    </para>
   </note>
+  <note>
+   <para>
+    <function>dirname</function> is locale aware, so for it to see the 
+    correct directory name with multibyte character paths, the matching locale must 
+    be set using the <function>setlocale</function> function.
+   </para>
+  </note>
   <note>
    <para>
     Since PHP 4.3.0, you will often get a slash or a dot back from