diff --git a/phpBB/styles/prosilver/theme/content.css b/phpBB/styles/prosilver/theme/content.css
index 1fd449d803..69ef22eab2 100644
--- a/phpBB/styles/prosilver/theme/content.css
+++ b/phpBB/styles/prosilver/theme/content.css
@@ -88,6 +88,10 @@ ul.topiclist dfn {
 	margin-right: 5px;
 }
 
+.forum-image img {
+	max-width: 100%;
+}
+
 li.row {
 	border-top: 1px solid transparent;
 	border-bottom: 1px solid transparent;