diff --git a/.verb.md b/.verb.md
index bdd7611..6075df0 100644
--- a/.verb.md
+++ b/.verb.md
@@ -9,10 +9,10 @@ Assuming you want to add a TOC to README.md:
 ```
 Usage: markdown-toc [options] <input>
 
-  input:        The Markdown file to parse for table of contents,
+  input:        The Markdown files to parse for table of contents,
                 or "-" to read from stdin.
 
-  -i:           Edit the <input> file directly, injecting the TOC at <!-- toc -->;
+  -i:           Edit the <input> files directly, injecting the TOC at <!-- toc -->;
                 (Without this flag, the default is to print the TOC to stdout.)
 
   --json:       Print the TOC in JSON format
diff --git a/README.md b/README.md
index b8766c4..9cc0e82 100644
--- a/README.md
+++ b/README.md
@@ -38,10 +38,10 @@ $ npm install --save markdown-toc
 ```
 Usage: markdown-toc [options] <input>
 
-  input:        The Markdown file to parse for table of contents,
+  input:        The Markdown files to parse for table of contents,
                 or "-" to read from stdin.
 
-  -i:           Edit the <input> file directly, injecting the TOC at <!-- toc -->;
+  -i:           Edit the <input> files directly, injecting the TOC at <!-- toc -->;
                 (Without this flag, the default is to print the TOC to stdout.)
 
   --json:       Print the TOC in JSON format
diff --git a/cli.js b/cli.js
index 87dd4c0..db1fcb2 100755
--- a/cli.js
+++ b/cli.js
@@ -12,14 +12,14 @@ var args = utils.minimist(process.argv.slice(2), {
   }
 });
 
-if (args._.length !== 1) {
+if (args._.length === 0) {
   console.error([
     'Usage: markdown-toc [options] <input> ',
     '',
-    '  input:        The Markdown file to parse for table of contents,',
+    '  input:        The Markdown files to parse for table of contents,',
     '                or "-" to read from stdin.',
     '',
-    '  -i:           Edit the <input> file directly, injecting the TOC at <!-- toc -->',
+    '  -i:           Edit the <input> files directly, injecting the TOC at <!-- toc -->',
     '                (Without this flag, the default is to print the TOC to stdout.)',
     '',
     '  --json:       Print the TOC in JSON format',
@@ -54,22 +54,23 @@ if (args.i && args._[0] === '-') {
   process.exit(1);
 }
 
-var input = process.stdin;
-if (args._[0] !== '-') input = fs.createReadStream(args._[0]);
+args._.forEach(function(filepath) {
+    var input = (filepath === '-') ? process.stdin : fs.createReadStream(filepath);
 
-input.pipe(utils.concat(function(input) {
-  if (args.i) {
-    var newMarkdown = toc.insert(input.toString(), args);
-    fs.writeFileSync(args._[0], newMarkdown);
-  } else {
-    var parsed = toc(input.toString(), args);
-    output(parsed);
-  }
-}));
+    input.pipe(utils.concat(function(input) {
+      if (args.i) {
+        var newMarkdown = toc.insert(input.toString(), args);
+        fs.writeFileSync(filepath, newMarkdown);
+      } else {
+        var parsed = toc(input.toString(), args);
+        output(parsed);
+      }
+    }));
 
-input.on('error', function onErr(err) {
-  console.error(err);
-  process.exit(1);
+    input.on('error', function onErr(err) {
+      console.error(err);
+      process.exit(1);
+    });
 });
 
 function output(parsed) {
diff --git a/test/test.js b/test/test.js
index e93e41b..c12dc59 100644
--- a/test/test.js
+++ b/test/test.js
@@ -427,3 +427,43 @@ describe('toc.insert', function() {
     assert.equal(strip(toc.insert(str, { linkify: false })), read('test/expected/insert-no-links.md'));
   });
 });
+
+describe('cli.js', function() {
+  describe('when provided two Markdon files', function() {
+    var hook;
+    beforeEach(function(){
+      hook = captureStream(process.stdout);
+    });
+    it('should build a ToC for both files"', function() {
+      process.argv= ["node", "cli.js", "test/fixtures/basic.md", "test/fixtures/levels.md"];
+      require('../cli');
+      setTimeout(function() {
+        hook.unhook();
+        assert.equal(hook.captured(), `- [AAA](#aaa)
+- [BBB](#bbb)
+- [CCC](#ccc)
+- [DDD](#ddd)- [AAA](#aaa)
+  * [a.1](#a1)
+    + [a.2](#a2)
+      - [a.3](#a3)`);
+      });
+    });
+  });
+});
+
+function captureStream(stream){
+  var oldWrite = stream.write;
+  var buf = '';
+  stream.write = function(chunk, encoding, callback){
+    buf += chunk.toString(); // chunk is a String or Buffer
+    oldWrite.apply(stream, arguments);
+  }
+  return {
+    unhook: function unhook() {
+     stream.write = oldWrite;
+    },
+    captured: function() {
+      return buf;
+    }
+  };
+}