diff --git a/phpBB/docs/INSTALL.html b/phpBB/docs/INSTALL.html
index d196403f62..581a26d2ad 100644
--- a/phpBB/docs/INSTALL.html
+++ b/phpBB/docs/INSTALL.html
@@ -151,6 +151,7 @@
 		<li>The following PHP modules are required:
 		<ul>
 			<li>json</li>
+			<li>mbstring</li>
 			<li>XML support</li>
 		</ul>
 		</li>