diff --git a/lib/url/escape.js b/lib/url/escape.js
index be9bd2c8..25074a6e 100644
--- a/lib/url/escape.js
+++ b/lib/url/escape.js
@@ -1,4 +1,7 @@
 module.exports = function escape(url) {
+    if (typeof url !== 'string') {
+        return url
+    }
     // If url is already wrapped in quotes, remove them
     if (/^['"].*['"]$/.test(url)) {
         url = url.slice(1, -1);
diff --git a/test/helpers.js b/test/helpers.js
index df0d14b6..5764527a 100644
--- a/test/helpers.js
+++ b/test/helpers.js
@@ -16,7 +16,7 @@ function getEvaluated(output, modules) {
 				return require("../lib/url/escape");
 			if(module.indexOf("-!/path/css-loader!") === 0)
 				module = module.substr(19);
-			if(modules && modules[module])
+			if(modules && module in modules)
 				return modules[module];
 			return "{" + module + "}";
 		});
diff --git a/test/urlTest.js b/test/urlTest.js
index 4690319c..543a47fe 100644
--- a/test/urlTest.js
+++ b/test/urlTest.js
@@ -125,6 +125,12 @@ describe("url", function() {
 	test("module from url-loader", ".class { background: green url(module) xyz }", [
 		[1, ".class { background: green url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAA) xyz }", ""]
 	], "", { './module': "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAA" });
+	test("module from null-loader (empty object from webpack)", ".class { background: green url(module) xyz }", [
+		[1, ".class { background: green url([object Object]) xyz }", ""]
+	], "", { './module': {} });
+	test("module is null", ".class { background: green url(module) xyz }", [
+		[1, ".class { background: green url(null) xyz }", ""]
+	], "", { './module': null });
 
 	test("background img with url", ".class { background: green url( \"img.png\" ) xyz }", [
 		[1, ".class { background: green url( \"img.png\" ) xyz }", ""]