diff --git a/lib/processCss.js b/lib/processCss.js
index 2e946827..ea8b31bc 100644
--- a/lib/processCss.js
+++ b/lib/processCss.js
@@ -77,30 +77,55 @@ var parserPlugin = postcss.plugin("css-loader-parser", function(options) {
 			exports[exportName] = replaceImportsInString(exports[exportName]);
 		});
 
+		function processNode(item, isValue) {
+			switch (item.type) {
+				case "value":
+					item.nodes.forEach(function(node){
+						processNode(node, true);
+					});
+					break;
+				case "nested-item":
+					item.nodes.forEach(function(node){
+						processNode(node);
+					});
+					break;
+				case "item":
+					var importIndex = imports["$" + item.name];
+					if (typeof importIndex === "number") {
+						item.name = "___CSS_LOADER_IMPORT___" + importIndex + "___";
+					}
+					break;
+				case "url":
+					if (!/^#/.test(item.url) && loaderUtils.isUrlRequest(item.url, options.root)) {
+						item.stringType = "";
+						delete item.innerSpacingBefore;
+						delete item.innerSpacingAfter;
+						var url;
+
+						if(isValue) {
+							if(loaderUtils.isUrlRequest(url, options.root) && options.mode === "global") {
+								url = loaderUtils.urlToRequest(item.url, options.root);
+							} else {
+								url = item.url;
+							}
+						} else {
+							url = item.url;
+						}
+
+						item.url = "___CSS_LOADER_URL___" + urlItems.length + "___";
+						urlItems.push({
+							url: url
+						});
+					}
+					break;
+			}
+		}
+
 		css.walkDecls(function(decl) {
 			var values = Tokenizer.parseValues(decl.value);
 			values.nodes.forEach(function(value) {
-				value.nodes.forEach(function(item) {
-					switch(item.type) {
-					case "item":
-						var importIndex = imports["$" + item.name];
-						if(typeof importIndex === "number") {
-							item.name = "___CSS_LOADER_IMPORT___" + importIndex + "___";
-						}
-						break;
-					case "url":
-						if(!/^#/.test(item.url) && loaderUtils.isUrlRequest(item.url, options.root)) {
-							item.stringType = "";
-							delete item.innerSpacingBefore;
-							delete item.innerSpacingAfter;
-							var url = item.url;
-							item.url = "___CSS_LOADER_URL___" + urlItems.length + "___";
-							urlItems.push({
-								url: url
-							});
-						}
-						break;
-					}
+				value.nodes.forEach(function(node){
+					processNode(node);
 				});
 			});
 			decl.value = Tokenizer.stringifyValues(values);
diff --git a/test/urlTest.js b/test/urlTest.js
index 3e583b94..daa91e3e 100644
--- a/test/urlTest.js
+++ b/test/urlTest.js
@@ -50,4 +50,7 @@ describe("url", function() {
 	test("keyframe background img", "@keyframes anim { background: green url('img.png') xyz }", [
 		[1, "@keyframes anim { background: green url({./img.png}) xyz }", ""]
 	]);
+	test("-webkit-image-set", "background-image: -webkit-image-set(url('url1x.png') 1x, url('url2x.png') 2x)", [
+		[1, "background-image: -webkit-image-set(url({./url1x.png}) 1x, url({./url2x.png}) 2x)", ""]
+	]);
 });