diff --git a/user_guide/changelog.html b/user_guide/changelog.html
index 3aaf729..e0e2bef 100644
--- a/user_guide/changelog.html
+++ b/user_guide/changelog.html
@@ -82,6 +82,7 @@
 	<li>Fixed bug in xss_clean() that could remove some desirable tag attributes.</li>
 	<li>Fixed assorted user guide typos or examples (#4840, #4862, #4864, #4899, #4930).</li>
 	<li>Fixed an edit from 1.6.3 that made the $robots array in user_agents.php go poof.</li>
+	<li>Fixed a bug in the Email library with quoted-printable encoding improperly encoding space and tab characters.</li>
 </ul>
 
 <h2>Version 1.6.3</h2>