diff --git a/lib/default-theme/SidebarLink.vue b/lib/default-theme/SidebarLink.vue
index 8e0e680410..b90329f00b 100644
--- a/lib/default-theme/SidebarLink.vue
+++ b/lib/default-theme/SidebarLink.vue
@@ -69,6 +69,8 @@ a.sidebar-link
   border-left 0.25rem solid transparent
   padding 0.35rem 1rem 0.35rem 1.25rem
   line-height 1.4
+  width: 100%
+  box-sizing: border-box
   &:hover
     color $accentColor
   &.active