diff --git a/less/mixins.less b/less/mixins.less
index b734bab2dc..4b09bea4cd 100644
--- a/less/mixins.less
+++ b/less/mixins.less
@@ -268,6 +268,12 @@
        -o-transition-delay: @transition-delay;
           transition-delay: @transition-delay;
 }
+.transition-duration(@transition-duration) {
+  -webkit-transition-duration: @transition-duration;
+     -moz-transition-duration: @transition-duration;
+       -o-transition-duration: @transition-duration;
+          transition-duration: @transition-duration;
+}
 
 // Transformations
 .rotate(@degrees) {