diff --git a/wp-includes/css/buttons.css b/wp-includes/css/buttons.css
index 219111bdcf..13f9881cae 100644
--- a/wp-includes/css/buttons.css
+++ b/wp-includes/css/buttons.css
@@ -27,7 +27,6 @@ TABLE OF CONTENTS:
  2.0 - Default Button Style
  3.0 - Primary Button Style
  4.0 - Button Groups
- 5.0 - Icon Buttons
 
 ---------------------------------------------------------------------------- */
 
@@ -287,50 +286,3 @@ input[type="submit"]::-moz-focus-inner {
 .button-group > .button:last-child {
 	border-radius: 0 3px 3px 0;
 }
-
-/* ----------------------------------------------------------------------------
-  5.0 - Icon Buttons
-
-  A button with a class of .down-arrow cannot have any input, and cannot have
-  any other content.
----------------------------------------------------------------------------- */
-.button.down-arrow:after {
-	content: '\25BE';
-	display: inline-block;
-	font-size: 16px;
-	opacity: 0.9;
-	margin: 0 -0.25em;
-	text-align: center;
-	vertical-align: middle;
-}
-
-.button .dropdown {
-	display: none;
-	position: absolute;
-	top: 100%;
-	left: 0;
-	margin: 5px 0;
-	padding: 0.8em 1em;
-	border-radius: 3px;
-
-	background: #f5f5f5;
-	color: #333;
-	text-shadow: none;
-	box-shadow:
-		0 0 0 1px rgba( 0, 0, 0, 0.3 ),
-		1px 1px 2px rgba( 0, 0, 0, 0.1 );
-}
-
-.button.active .dropdown {
-	display: block;
-}
-
-.dropdown-flip-x .dropdown {
-	left: auto;
-	right: 0;
-}
-
-.dropdown-flip-y .dropdown {
-	top: auto;
-	bottom: 100%;
-}
\ No newline at end of file