diff --git a/docs/manual/CoreTypes/propertyset.html b/docs/manual/CoreTypes/propertyset.html
index 8b642c6ec..efb5eba1a 100644
--- a/docs/manual/CoreTypes/propertyset.html
+++ b/docs/manual/CoreTypes/propertyset.html
@@ -54,7 +54,7 @@ set.</p>
     <td valign="top">Select the properties that match the given
       regular expression.  Similar to <a
       href="mapper.html#regexp-mapper">regexp type mappers</a>, this
-      equires a supported regular expression library.</td>
+      requires a supported regular expression library.</td>
   </tr>
   <tr>
     <td valign="top">builtin</td>