diff --git a/assets/default/css/theme.css b/assets/default/css/theme.css
index b4cece6ef42e87459327f5f087069ceac6c876e3..86e8dabb472701c7b296820ce73b77c07c0bda16 100644
--- a/assets/default/css/theme.css
+++ b/assets/default/css/theme.css
@@ -1064,7 +1064,7 @@ img.avatar {
 }
 .avatar > img.avatar {
     width: 100%;
-    height: 100%;
+    height: auto;
 }
 .thread-entry .header {
     padding: 8px 0.9em;