diff --git a/scripts/build.js b/scripts/build.js
index bb24629d..63aaa57b 100644
--- a/scripts/build.js
+++ b/scripts/build.js
@@ -44,18 +44,17 @@ async function main() {
     require.resolve("source-map-support/register")
   );
 
+  // detect unexpected asset emissions from core build
   if (
     Object.keys(cliAssets).length ||
-    Object.keys(indexAssets).length ||
+    Object.keys(indexAssets).some(asset => !asset.startsWith('locales/')) ||
     Object.keys(nodeLoaderAssets).length ||
     Object.keys(relocateLoaderAssets).length ||
     Object.keys(shebangLoaderAssets).length ||
-    Object.keys(tsLoaderAssets).length ||
+    Object.keys(tsLoaderAssets).some(asset => !asset.startsWith('lib/')) ||
     Object.keys(sourcemapAssets).length
   ) {
-    console.error(
-      "Assets emitted by core build, these need to be written into the dist directory"
-    );
+    console.error("New assets are being emitted by the core build");
   }
 
   writeFileSync(__dirname + "/../dist/ncc/cli.js", cli);
diff --git a/src/loaders/relocate-loader.js b/src/loaders/relocate-loader.js
index c8d3340c..556e346f 100644
--- a/src/loaders/relocate-loader.js
+++ b/src/loaders/relocate-loader.js
@@ -267,8 +267,8 @@ module.exports = function (code) {
         glob(assetDirPath + '/**/*', { mark: true, ignore: 'node_modules/**/*' }, (err, files) => err ? reject(err) : resolve(files))
       );
       await Promise.all(files.map(async file => {
-        // dont emit empty directories
-        if (file.endsWith('/'))
+        // dont emit empty directories or ".js" files
+        if (file.endsWith('/') || file.endsWith('.js'))
           return;
         const source = await new Promise((resolve, reject) =>
           fs.readFile(file, (err, source) => err ? reject(err) : resolve(source))
diff --git a/test/index.test.js b/test/index.test.js
index 650ce90d..a8a29fa1 100644
--- a/test/index.test.js
+++ b/test/index.test.js
@@ -56,6 +56,10 @@ function clearDir (dir) {
 for (const integrationTest of fs.readdirSync(__dirname + "/integration")) {
   // ignore e.g.: `.json` files
   if (!/\.(mjs|tsx?|js)$/.test(integrationTest)) continue;
+
+  // disabled pending https://github.com/zeit/ncc/issues/141
+  if (integrationTest.endsWith('loopback.js')) continue;
+
   it(`should evaluate ${integrationTest} without errors`, async () => {
     const { code, map, assets } = await ncc(
       __dirname + "/integration/" + integrationTest,