diff --git a/web/viewer.css b/web/viewer.css
index 512dec87c..8268fcd20 100644
--- a/web/viewer.css
+++ b/web/viewer.css
@@ -408,6 +408,8 @@ body {
 .thumbnail {
   margin-bottom: 15px;
   float: left;
+  width: 114px;
+  height: 142px;
 }
 
 .thumbnailImage {