diff --git a/reference/filesystem/functions/realpath.xml b/reference/filesystem/functions/realpath.xml
index 92d7161567..b3488ad274 100644
--- a/reference/filesystem/functions/realpath.xml
+++ b/reference/filesystem/functions/realpath.xml
@@ -15,7 +15,7 @@
   <para>
    <function>realpath</function> expands all symbolic links and
    resolves references to '/./', '/../' and extra '/' characters in
-   the input <parameter>path</parameter>. and return the canonicalized
+   the input <parameter>path</parameter> and return the canonicalized
    absolute pathname.  
   </para>
  </refsect1>
@@ -46,6 +46,13 @@
    <function>realpath</function> returns &false; on failure, e.g. if
    the file does not exist.
   </para>
+  <note>
+   <para>
+    The running script must have executable permissions on all directories in
+    the hierarchy, otherwise <function>realpath</function> will return
+    &false;.
+   </para>
+  </note>
  </refsect1>
 
  <refsect1 role="changelog">