diff --git a/src/compiler/compile/render_dom/index.ts b/src/compiler/compile/render_dom/index.ts
index 062b85090a..e542e3ab83 100644
--- a/src/compiler/compile/render_dom/index.ts
+++ b/src/compiler/compile/render_dom/index.ts
@@ -1,5 +1,5 @@
 import { b, x, p } from 'code-red';
-import { stringify, escape } from '../utils/stringify';
+import { escape } from '../utils/stringify';
 import Component from '../Component';
 import Renderer from './Renderer';
 import { CompileOptions } from '../../interfaces';
@@ -26,7 +26,7 @@ export default function dom(
 
 	const body = [];
 
-	if (component.compile_options.dev && component.file) {
+	if (renderer.file_var) {
 		body.push(b`const ${renderer.file_var} = "${component.file}";`);
 	}
 
diff --git a/test/custom-elements/assert.js b/test/custom-elements/assert.js
index 79aba6c736..0edbd31124 100644
--- a/test/custom-elements/assert.js
+++ b/test/custom-elements/assert.js
@@ -1,3 +1,29 @@
+export function deepEqual(a, b, message) {
+	if (!is_equal(a, b)) {
+		throw new Error(message || `Expected ${JSON.stringify(a)} to equal ${JSON.stringify(b)}`);
+	}
+}
+
+function is_equal(a, b) {
+	if (a && typeof a === 'object') {
+		const is_array = Array.isArray(a);
+		if (Array.isArray(b) !== is_array) return false;
+
+		if (is_array) {
+			if (a.length !== b.length) return false;
+			return a.every((value, i) => is_equal(value, b[i]));
+		}
+
+		const a_keys = Object.keys(a).sort();
+		const b_keys = Object.keys(b).sort();
+		if (a_keys.join(',') !== b_keys.join(',')) return false;
+
+		return a_keys.every(key => is_equal(a[key], b[key]));
+	}
+
+	return a === b;
+}
+
 export function equal(a, b, message) {
 	if (a != b) throw new Error(message || `Expected ${a} to equal ${b}`);
 }
diff --git a/test/custom-elements/index.js b/test/custom-elements/index.js
index 9255d33c0e..7fe47f2ecd 100644
--- a/test/custom-elements/index.js
+++ b/test/custom-elements/index.js
@@ -109,6 +109,11 @@ describe('custom-elements', function() {
 				console[type](...args);
 			});
 
+			page.on('error', error => {
+				console.log('>>> an error happened');
+				console.error(error);
+			});
+
 			try {
 				await page.goto('http://localhost:6789');
 
diff --git a/test/custom-elements/samples/no-missing-prop-warnings/test.js b/test/custom-elements/samples/no-missing-prop-warnings/test.js
index e7ced25e19..1909e7aef9 100644
--- a/test/custom-elements/samples/no-missing-prop-warnings/test.js
+++ b/test/custom-elements/samples/no-missing-prop-warnings/test.js
@@ -11,8 +11,9 @@ export default function (target) {
 
 	target.innerHTML = '<my-app foo=yes />';
 
-	assert.equal(warnings.length, 1);
-	assert.equal(warnings[0], `<my-app> was created without expected prop 'bar'`);
+	assert.deepEqual(warnings, [
+		`<my-app> was created without expected prop 'bar'`
+	]);
 
 	console.warn = warn;
 }
\ No newline at end of file