diff --git a/less/mixins.less b/less/mixins.less
index 104590730dec..a17103975a97 100644
--- a/less/mixins.less
+++ b/less/mixins.less
@@ -54,7 +54,6 @@
 
 // Placeholder text
 .placeholder(@color: @input-color-placeholder) {
-  &:-moz-placeholder            { color: @color; } // Firefox 4-18
   &::-moz-placeholder           { color: @color;   // Firefox 19+
                                   opacity: 1; } // See https://github.com/twbs/bootstrap/pull/11526
   &:-ms-input-placeholder       { color: @color; } // Internet Explorer 10+