diff --git a/frontend/less/dark-vertical/variables.less b/frontend/less/dark-vertical/variables.less
index ed8e357f1f..1821326e16 100644
--- a/frontend/less/dark-vertical/variables.less
+++ b/frontend/less/dark-vertical/variables.less
@@ -80,7 +80,7 @@
 @dropdown-link-hover-color-value: lighten(@text-color-value, 5%);
 @dropdown-link-hover-bg-value: #2c2b2b;
 @dropdown-divider-bg-value: @default-border-color-value;
-@dropdown-border-value: #403f3f;
+@dropdown-border-value: transparent;
 
 @select-item-bg-value: @default-heading-bg-color-value;
 @select-item-border-value: @btn-default-border-value;