diff --git a/frontend/app/components/comment/_level/comment_level.scss b/frontend/app/components/comment/_level/comment_level.scss
index ab9f45ff..eaf43958 100644
--- a/frontend/app/components/comment/_level/comment_level.scss
+++ b/frontend/app/components/comment/_level/comment_level.scss
@@ -5,6 +5,3 @@
 .thread_level_4 .thread > .thread {
   padding-left: 5px;
 }
-.comment_theme_dark ~ .thread {
-  border-left-color: rgba(255, 255, 255, 0.15);
-}
diff --git a/frontend/app/components/comment/_theme/_dark/comment_theme_dark.scss b/frontend/app/components/comment/_theme/_dark/comment_theme_dark.scss
index d6b17955..6977509f 100644
--- a/frontend/app/components/comment/_theme/_dark/comment_theme_dark.scss
+++ b/frontend/app/components/comment/_theme/_dark/comment_theme_dark.scss
@@ -97,4 +97,8 @@
       }
     }
   }
+
+  & ~ .thread {
+    border-left-color: rgba(255, 255, 255, 0.15);
+  }
 }