diff --git a/lib/capybara/node/actions.rb b/lib/capybara/node/actions.rb
index 94676d48..aa9faa35 100644
--- a/lib/capybara/node/actions.rb
+++ b/lib/capybara/node/actions.rb
@@ -312,7 +312,7 @@ module Capybara
         var css = arguments[0];
         for (var prop in css){
           if (css.hasOwnProperty(prop)) {
-            this.style[prop] = css[prop]
+            this.style.setProperty(prop, css[prop], "important");
           }
         }
       JS