diff --git a/bin/uglifyjs b/bin/uglifyjs
index 62c7beb3..61678198 100755
--- a/bin/uglifyjs
+++ b/bin/uglifyjs
@@ -1,4 +1,4 @@
-#! /usr/bin/env node
+#! /usr/bin/env node
 // -*- js -*-
 
 "use strict";
@@ -169,6 +169,9 @@ if (program.self) {
     });
     process.stdin.resume();
 }
+if (!program.args.length){
+   program.help();
+}
 
 function convert_ast(fn) {
     return UglifyJS.AST_Node.from_mozilla_ast(Object.keys(files).reduce(fn, null));
diff --git a/package-lock.json b/package-lock.json
new file mode 100644
index 00000000..7c86551b
--- /dev/null
+++ b/package-lock.json
@@ -0,0 +1,30 @@
+{
+  "name": "uglify-js",
+  "version": "3.4.9",
+  "lockfileVersion": 1,
+  "requires": true,
+  "dependencies": {
+    "acorn": {
+      "version": "5.7.3",
+      "resolved": "https://registry.npmjs.org/acorn/-/acorn-5.7.3.tgz",
+      "integrity": "sha512-T/zvzYRfbVojPWahDsE5evJdHb3oJoQfFbsrKM7w5Zcs++Tr257tia3BmMP8XYVjp1S9RZXQMh7gao96BlqZOw==",
+      "dev": true
+    },
+    "commander": {
+      "version": "2.17.1",
+      "resolved": "https://registry.npmjs.org/commander/-/commander-2.17.1.tgz",
+      "integrity": "sha512-wPMUt6FnH2yzG95SA6mzjQOEKUU3aLaDEmzs1ti+1E9h+CsrZghRlqEM/EJ4KscsQVG8uNN4uVreUeT8+drlgg=="
+    },
+    "semver": {
+      "version": "5.5.1",
+      "resolved": "https://registry.npmjs.org/semver/-/semver-5.5.1.tgz",
+      "integrity": "sha512-PqpAxfrEhlSUWge8dwIp4tZnQ25DIOthpiaHNIthsjEFQD6EvqUKUDM7L8O2rShkFccYo1VjJR0coWfNkCubRw==",
+      "dev": true
+    },
+    "source-map": {
+      "version": "0.6.1",
+      "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.6.1.tgz",
+      "integrity": "sha512-UjgapumWlbMhkBgzT7Ykc5YXUT46F0iKu8SGXq0bcwP5dz/h0Plj6enJqjz1Zbq2l5WaqYnrVbwWOWMyF3F47g=="
+    }
+  }
+}