diff --git a/dist/less/selectize.less b/dist/less/selectize.less
index bd2df979c..7fa29f604 100644
--- a/dist/less/selectize.less
+++ b/dist/less/selectize.less
@@ -265,7 +265,7 @@
 		position: absolute;
 		top: 50%;
 		right: @selectize-arrow-offset;
-		margin-top: round(-1 * @selectize-arrow-size / 2);
+		margin-top: round((-1 * @selectize-arrow-size / 2));
 		width: 0;
 		height: 0;
 		border-style: solid;
diff --git a/src/less/selectize.less b/src/less/selectize.less
index 7a2a8047d..ee1d9434d 100644
--- a/src/less/selectize.less
+++ b/src/less/selectize.less
@@ -260,7 +260,7 @@
 		position: absolute;
 		top: 50%;
 		right: @selectize-arrow-offset;
-		margin-top: round(-1 * @selectize-arrow-size / 2);
+		margin-top: round((-1 * @selectize-arrow-size / 2));
 		width: 0;
 		height: 0;
 		border-style: solid;