--- a/devtools/client/themes/webconsole.css
+++ b/devtools/client/themes/webconsole.css
@@ -784,16 +784,17 @@ a.learn-more-link.webconsole-learn-more-
   flex: 1 1 100%;
 }
 
 .webconsole-filterbar-primary .filter-checkbox {
   flex-shrink: 0;
   margin: 0 3px;
   display: flex;
   align-items: center;
+  -moz-user-select: none;
 }
 
 .webconsole-filterbar-secondary .devtools-separator {
   margin: 0 5px;
 }
 
 .webconsole-filterbar-filtered-messages {
   /* Needed so the bar takes the whole horizontal space when it is wrapped */