diff --git a/.travis.yml b/.travis.yml
index f3e544fc..7d1bec72 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,4 +5,4 @@ node_js:
 
 before_install: npm install -g grunt-cli
 
-script: grunt travis
+script: grunt travis && ./scripts/post-coverage.sh
diff --git a/Gruntfile.js b/Gruntfile.js
index ecf0d6bb..2daf0608 100644
--- a/Gruntfile.js
+++ b/Gruntfile.js
@@ -33,8 +33,8 @@ module.exports = function(grunt) {
       },
       test: {
         files: {
-          'build/tests.js': ['test/**/*-test.js']
-        },
+          'build/tests.js': ['src/**/*.js', 'test/**/*-test.js', '!src/main.js']
+        }
       },
       options: {
         transform: [
@@ -51,8 +51,34 @@ module.exports = function(grunt) {
         }
       }
     },
+    jscoverage: {
+      src: {
+        expand: true,
+        cwd: 'build/',
+        src: ['tests.js'],
+        dest: 'build/cov/',
+        ext: '.js'
+      }
+    },
+    exorcise: {
+      bundle: {
+        options: {},
+        files: {
+          'build/tests.map': ['build/tests.js'],  // externalize source map
+        }
+      }
+    },
     mocha_phantomjs: {
-      all: ['test/**/*.html']
+      run: {
+        src: ['test/runner.html']
+      },
+      cov: {
+        src: ['test/coverage.html'],
+        options: {
+          reporter: 'test/lcov-reporter.js',
+          output: 'build/bundled.lcov'
+        }
+      }
     }
   });
 
@@ -60,11 +86,15 @@ module.exports = function(grunt) {
   grunt.loadNpmTasks('grunt-contrib-watch');
   grunt.loadNpmTasks('grunt-flow-type-check');
   grunt.loadNpmTasks('grunt-mocha-phantomjs');
+  grunt.loadNpmTasks("grunt-jscoverage");
+  grunt.loadNpmTasks("grunt-exorcise");
 
   grunt.registerTask('watchFlow', ['flow:app:start', 'watch:flow']);
   grunt.registerTask('watchFlowProd', ['flow:app:start', 'watch:flowProd']);
   grunt.registerTask('prod', ['browserify:dist']);
   grunt.registerTask('browsertests', ['browserify:test']);
-  grunt.registerTask('test', ['browsertests', 'mocha_phantomjs']);
+  grunt.registerTask('test', ['browsertests', 'mocha_phantomjs:run']);
   grunt.registerTask('travis', ['flow', 'test']);
+  grunt.registerTask('coverage',
+                     ['browsertests', 'exorcise', 'jscoverage', 'mocha_phantomjs:cov']);
 };
diff --git a/package.json b/package.json
index 9ff1b834..eb7a2400 100644
--- a/package.json
+++ b/package.json
@@ -20,19 +20,26 @@
   },
   "devDependencies": {
     "chai": "^2.0.0",
+    "coveralls": "^2.11.2",
     "es5-shim": "^4.1.0",
     "flow-bin": "^0.4.0",
     "grunt": "^0.4.5",
     "grunt-browserify": "^3.3.0",
     "grunt-contrib-watch": "^0.6.1",
     "grunt-env": "^0.4.2",
+    "grunt-exorcise": "^1.0.0",
     "grunt-flow-type-check": "^0.4.2",
+    "grunt-jscoverage": "^0.1.3",
     "grunt-mocha-phantomjs": "^0.6.0",
     "grunt-mocha-test": "^0.12.7",
+    "lcov-parse": "0.0.9",
     "mocha": "^2.1.0",
+    "mocha-lcov-reporter": "0.0.1",
+    "parse-data-uri": "^0.2.0",
     "react-tools": "^0.12.2",
     "reactify": "^1.0.0",
     "sinon": "^1.12.2",
+    "source-map": "^0.3.0",
     "text-encoding": "^0.5.2"
   }
 }
diff --git a/scripts/post-coverage.sh b/scripts/post-coverage.sh
new file mode 100755
index 00000000..2c304f6c
--- /dev/null
+++ b/scripts/post-coverage.sh
@@ -0,0 +1,13 @@
+#!/bin/bash
+# Generate code coverage and post it to Coveralls.
+set -o errexit
+set -x
+
+# Generate LCOV data for the bundled tests
+grunt coverage
+
+# Convert code coverage data on the bundled test file back to the originals.
+./scripts/transform-coverage.js \
+  build/tests.map \
+  build/bundled.lcov \
+  | ./node_modules/.bin/coveralls
diff --git a/scripts/transform-coverage.js b/scripts/transform-coverage.js
new file mode 100755
index 00000000..e33fcead
--- /dev/null
+++ b/scripts/transform-coverage.js
@@ -0,0 +1,66 @@
+#!/usr/bin/env node
+/**
+ * This script applies a source map to LCOV data. If you have coverage data for
+ * a concatenated file, plus a source map, this will output LCOV data for your
+ * original source files.
+ *
+ * Usage:
+ *
+ *   transform-coverage.js path/to/soure.map path/to/coverage.lcov > out.lcov
+ */
+
+var sourcemap = require('source-map');
+var fs = require('fs');
+var parseDataUri = require('parse-data-uri')
+var lcovParse = require('lcov-parse');
+var assert = require('assert');
+
+var sourcemapfile = process.argv[2];
+var lcovfile = process.argv[3];
+
+var sourcemap_data = fs.readFileSync(sourcemapfile).toString();
+var sourcemap_consumer = new sourcemap.SourceMapConsumer(sourcemap_data);
+
+var SOURCE = 'src/';
+
+lcovParse(lcovfile, function(err, data) {
+  assert(!err);
+  // TODO: 0 --> the correct file
+  var lines = data[0].lines.details;
+
+  var fileToCov = {};  // filename -> { line num -> hits }
+
+  lines.forEach(function(line) {
+    var num = line.line, hits = line.hit;
+    var original_position = sourcemap_consumer.originalPositionFor({ line: num, column: 0 });
+    if (original_position == null) {
+      return;
+    }
+
+    original_filename = original_position.source;
+    original_num = original_position.line;
+
+    if (!original_filename || original_filename.indexOf('node_modules') >= 0) {
+      return;
+    }
+
+    var base = original_filename.indexOf(SOURCE);
+    if (base == -1) return;
+    original_filename = original_filename.slice(base);
+
+    if (!fileToCov[original_filename]) fileToCov[original_filename] = [];
+    fileToCov[original_filename][original_num] = hits;
+  });
+
+  // Convert to LCOV format
+  for (var filename in fileToCov) {
+    var cov = fileToCov[filename]
+    console.log('SF:' + filename);
+    for (var i = 0; i < cov.length; i++) {
+      if (cov[i] != null) {
+        console.log('DA:' + i + ',' + cov[i]);
+      }
+    }
+    console.log('end_of_record');
+  }
+});
diff --git a/test/RemoteFile-test.js b/test/RemoteFile-test.js
index fe55f2a2..f3b78c0d 100644
--- a/test/RemoteFile-test.js
+++ b/test/RemoteFile-test.js
@@ -13,12 +13,12 @@ describe('RemoteFile', () => {
     FakeXHR.restore();
   });
 
-  it('should fetch a subset of a file', () => {
+  it('should fetch a subset of a file', (done) => {
     FakeXHR.addResponse('http://example.com/file.txt',
                         new TextEncoder('utf-8').encode('01234567890').buffer);
 
     var f = new RemoteFile('http://example.com/file.txt');
-    var promisedData = f.getBytes(10, 20);
+    var promisedData = f.getBytes(10, 11);
 
     expect(FakeXHR.numRequests).to.equal(1);
     // expect(req.requestHeaders.Range).to.equal('bytes=10-29');
diff --git a/test/coverage.html b/test/coverage.html
new file mode 100644
index 00000000..74b456af
--- /dev/null
+++ b/test/coverage.html
@@ -0,0 +1,32 @@
+<html>
+<head>
+  <meta charset="utf-8">
+  <title>pileup.js Tests</title>
+  <link rel="stylesheet" href="../node_modules/mocha/mocha.css" />
+</head>
+<body>
+  <div id="mocha"></div>
+
+  <!-- Polyfills for PhantomJS -->
+  <script src="../node_modules/es5-shim/es5-shim.min.js"></script>
+  <script src="../node_modules/es5-shim/es5-sham.min.js"></script>
+  <script src="../node_modules/text-encoding/lib/encoding.js"></script>
+
+  <!-- Mocha -->
+  <script src="../node_modules/mocha/mocha.js"></script>
+  <script>mocha.setup('bdd')</script>
+
+  <!--<script src="../build/cov/tests-debug.js"></script>-->
+  <!--<script src="../build/tests-debug.js"></script>-->
+  <script src="../build/cov/tests.js"></script>
+
+  <script>
+    mocha.checkLeaks();
+    if (window.mochaPhantomJS) {
+      mochaPhantomJS.run();
+    } else {
+      mocha.run();
+    }
+  </script>
+</body>
+</html>
diff --git a/test/lcov-reporter.js b/test/lcov-reporter.js
new file mode 100644
index 00000000..fb4c16dc
--- /dev/null
+++ b/test/lcov-reporter.js
@@ -0,0 +1,44 @@
+// See https://github.com/StevenLooman/mocha-lcov-reporter/pull/7
+
+/**
+ * Expose `LCov`.
+ */
+
+exports = module.exports = LCov;
+
+/**
+ * Initialize a new LCOV reporter.
+ * File format of LCOV can be found here: http://ltp.sourceforge.net/coverage/lcov/geninfo.1.php
+ * The reporter is built after this parser: https://raw.github.com/SonarCommunity/sonar-javascript/master/sonar-javascript-plugin/src/main/java/org/sonar/plugins/javascript/coverage/LCOVParser.java
+ *
+ * @param {Runner} runner
+ * @api public
+ */
+
+function LCov(runner) {
+  runner.on('end', function(){
+    // In a browser context, coverage will be in window.$jscoverage.
+    var g = typeof(global) != 'undefined' ? global : window;
+    var cov = g._$jscoverage || {};
+
+    for (var filename in cov) {
+      var data = cov[filename];
+      reportFile(filename, data);
+    }
+  });
+}
+
+function reportFile(filename, data) {
+  process.stdout.write('SF:' + filename + '\n');
+
+  data.source.forEach(function(line, num) {
+    // increase the line number, as JS arrays are zero-based
+    num++;
+
+    if (data[num] !== undefined) {
+      process.stdout.write('DA:' + num + ',' + data[num] + '\n');
+    }
+  });
+
+  process.stdout.write('end_of_record\n');
+}