diff --git a/less/mixins.less b/less/mixins.less
index b5beaddf28..1a2a97ae4f 100644
--- a/less/mixins.less
+++ b/less/mixins.less
@@ -353,7 +353,7 @@
 //
 // Keep images from scaling beyond the width of their parents.
 
-.img-responsive(@display: block;) {
+.img-responsive(@display: block) {
   display: @display;
   max-width: 100%; // Part 1: Set a maximum relative to the parent
   height: auto; // Part 2: Scale the height according to the width, otherwise you get stretching