diff --git a/phpBB/docs/CHANGELOG.html b/phpBB/docs/CHANGELOG.html
index cbd138a0bc..16682ddd7d 100644
--- a/phpBB/docs/CHANGELOG.html
+++ b/phpBB/docs/CHANGELOG.html
@@ -235,6 +235,7 @@ p a {
 		<li>[Fix] Fixed bug in realpath replacement letting it actually work again</li>
 		<li>[Change] Try to be a bit more specific regarding global/local permission trace (Bug #11032)</li>
 		<li>[Fix] Fixed some strangeness in password validation due to mb_ereg()</li>
+		<li>[Fix] Subforums of a forum would overwrite the latest post information even if they did not contain the latest post (Bug #11931)</li>
 
 	</ul>
 
diff --git a/phpBB/includes/functions_display.php b/phpBB/includes/functions_display.php
index 626e1d6dd9..f01377b2ab 100644
--- a/phpBB/includes/functions_display.php
+++ b/phpBB/includes/functions_display.php
@@ -216,7 +216,7 @@ function display_forums($root_data = '', $display_moderators = true, $return_mod
 				$forum_rows[$parent_id]['forum_last_poster_colour'] = $row['forum_last_poster_colour'];
 				$forum_rows[$parent_id]['forum_id_last_post'] = $forum_id;
 			}
-			else
+			else if (!isset($forum_rows[$parent_id]['forum_id_last_post']))
 			{
 				$forum_rows[$parent_id]['forum_id_last_post'] = $forum_id;
 			}