--- a/toolkit/themes/shared/in-content/common.inc.css
+++ b/toolkit/themes/shared/in-content/common.inc.css
@@ -894,24 +894,16 @@ xul|treecol:not([hideheader="true"]) > x
   width: 18px;
   height: 18px;
 }
 
 xul|treecol:not([hideheader="true"]) > xul|*.treecol-sortdirection[sortDirection="ascending"] {
   transform: scaleY(-1);
 }
 
-xul|treecol > xul|label.treecol-text {
-  font-size: 1rem;
-}
-
-xul|treechildren {
-  font-size: 1rem !important;
-}
-
 /* This is the only way to increase the height of a tree row unfortunately */
 xul|treechildren::-moz-tree-row {
   min-height: 2em;
 }
 
 /* Color needs to be set on tree cell in order to be applied */
 xul|treechildren::-moz-tree-cell-text {
   color: var(--in-content-text-color);