diff --git a/src/vs/base/browser/ui/selectBox/selectBoxCustom.css b/src/vs/base/browser/ui/selectBox/selectBoxCustom.css
index 664d38f170910..292cd2dd1e19e 100644
--- a/src/vs/base/browser/ui/selectBox/selectBoxCustom.css
+++ b/src/vs/base/browser/ui/selectBox/selectBoxCustom.css
@@ -41,6 +41,8 @@
 	text-align: left;
 	width: 1px;
 	overflow: hidden;
+	border-bottom-left-radius: 3px;
+	border-bottom-right-radius: 3px;
 }
 
 .monaco-select-box-dropdown-container > .select-box-dropdown-list-container {