diff --git a/browser/themes/shared/sidebar.inc.css b/browser/themes/shared/sidebar.inc.css
index c0140d222231..68ffaedb2e2a 100644
--- a/browser/themes/shared/sidebar.inc.css
+++ b/browser/themes/shared/sidebar.inc.css
@@ -16,10 +16,10 @@
   border: 0 solid;
   border-inline-end-width: 1px;
   min-width: 1px;
-  width: 3px;
+  width: 8px;
   background-image: none !important;
   background-color: transparent;
-  margin-inline-start: -3px;
+  margin-inline-start: -8px;
   position: relative;
 }
 
@@ -27,7 +27,7 @@
   border-inline-end-width: 0;
   border-inline-start-width: 1px;
   margin-inline-start: 0;
-  margin-inline-end: -3px;
+  margin-inline-end: -8px;
 }
 
 #sidebar-throbber[loading="true"] {