diff --git a/src/css/support.js b/src/css/support.js
index 4a8fc87ac..05f5cc866 100644
--- a/src/css/support.js
+++ b/src/css/support.js
@@ -120,6 +120,8 @@ define([
 
 			reliableMarginRightVal =
 				!parseFloat( ( window.getComputedStyle( contents, null ) || {} ).marginRight );
+
+			div.removeChild( contents );
 		}
 
 		// Support: IE8