diff --git a/lib/processCss.js b/lib/processCss.js
index 0fa9bcc7..95865ce7 100644
--- a/lib/processCss.js
+++ b/lib/processCss.js
@@ -154,7 +154,7 @@ module.exports = function processCss(inputSource, inputMap, options, callback) {
 	]);
 
 	if(minimize) {
-		var minimizeOptions = Object.create(query);
+		var minimizeOptions = Object.assign({}, query);
 		["zindex", "normalizeUrl", "discardUnused", "mergeIdents", "reduceIdents"].forEach(function(name) {
 			if(typeof minimizeOptions[name] === "undefined")
 				minimizeOptions[name] = false;