diff --git a/bin/install.js b/bin/install.js
index c6cd0cfd..7fd91ae0 100755
--- a/bin/install.js
+++ b/bin/install.js
@@ -99,6 +99,11 @@ Options:
 
 const pkgs = [];
 
+if (process.env.NPMINSTALL_BY_UPDATE) {
+  // ignore all package names on update
+  argv._ = [];
+}
+
 for (const name of argv._) {
   const p = npa(String(name));
   pkgs.push({ name: p.name, version: p.rawSpec, type: p.type });
diff --git a/bin/update.js b/bin/update.js
index d5b33724..b25007ae 100755
--- a/bin/update.js
+++ b/bin/update.js
@@ -25,6 +25,9 @@ const nodeModules = path.join(root, 'node_modules');
 console.log('[npmupdate] removing %s', nodeModules);
 rimraf.sync(nodeModules);
 console.log('[npmupdate] reinstall on %s', root);
+
+// make sure install ignore all package names
+process.env.NPMINSTALL_BY_UPDATE = 'true';
 require('./install');
 
 function help() {
diff --git a/test/update.test.js b/test/update.test.js
index 3326da44..b9bd4c92 100644
--- a/test/update.test.js
+++ b/test/update.test.js
@@ -27,7 +27,7 @@ describe('test/update.test.js', () => {
 
   afterEach(cleanup);
 
-  it('should uninstall ok', done => {
+  it('should update ok', done => {
     coffee.fork(npmupdate, [], {
       cwd: root,
       stdio: 'pipe',
@@ -40,4 +40,18 @@ describe('test/update.test.js', () => {
       done();
     });
   });
+
+  it('should update pedding ok', done => {
+    coffee.fork(npmupdate, [ 'pedding' ], {
+      cwd: root,
+      stdio: 'pipe',
+    })
+    .debug()
+    .end(err => {
+      assert(!err);
+      assert(fs.existsSync(path.join(root, 'node_modules/pedding')));
+      assert(fs.existsSync(path.join(root, 'node_modules/pkg')));
+      done();
+    });
+  });
 });