diff --git a/assets/css/screen.css b/assets/css/screen.css
index a68100c..9fb89ec 100644
--- a/assets/css/screen.css
+++ b/assets/css/screen.css
@@ -275,6 +275,11 @@ table.plain {
     display: block;
     width: 100%;
     height: auto;
+    -webkit-user-select: none;
+    -khtml-user-select: none;
+    -moz-user-select: none;
+    -o-user-select: none;
+    user-select: none;
 }
 
 #sitehead .wrap {