diff --git a/.travis.yml b/.travis.yml
index c159f6a..48bd1a9 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,3 +1,18 @@
 language: node_js
 node_js:
   - lts/*
+env:
+  global:
+    - MOZ_HEADLESS=1
+services:
+  - xvfb
+addons:
+  firefox: latest
+  chrome: stable
+cache:
+  npm: false
+
+script:
+  - npm test
+  - xvfb-run --auto-servernum npm run test-browser -- --browser chrome
+  - xvfb-run --auto-servernum npm run test-browser -- --browser firefox
diff --git a/crypto_verify.js b/crypto_verify.js
index 1dfe154..f23ff3d 100644
--- a/crypto_verify.js
+++ b/crypto_verify.js
@@ -1,11 +1,7 @@
 /* eslint-disable camelcase */
-const assert = require('nanoassert')
-
 module.exports = {
   crypto_verify_16,
-  crypto_verify_32,
-  sodium_memcmp,
-  sodium_is_zero
+  crypto_verify_32
 }
 
 function vn (x, xi, y, yi, n) {
@@ -14,6 +10,11 @@ function vn (x, xi, y, yi, n) {
   return (1 & ((d - 1) >>> 8)) - 1
 }
 
+// Make non enumerable as this is an internal function
+Object.defineProperty(module.exports, 'vn', {
+  value: vn
+})
+
 function crypto_verify_16 (x, xi, y, yi) {
   return vn(x, xi, y, yi, 16)
 }
@@ -21,15 +22,3 @@ function crypto_verify_16 (x, xi, y, yi) {
 function crypto_verify_32 (x, xi, y, yi) {
   return vn(x, xi, y, yi, 32)
 }
-
-function sodium_memcmp (a, b) {
-  assert(a.byteLength === b.byteLength, 'buffers must be the same size')
-
-  return vn(a, 0, b, 0, a.byteLength) === 0
-}
-
-function sodium_is_zero (arr) {
-  var d = 0
-  for (let i = 0; i < arr.length; i++) d |= arr[i]
-  return d === 0
-}
diff --git a/helpers.js b/helpers.js
new file mode 100644
index 0000000..389f5c1
--- /dev/null
+++ b/helpers.js
@@ -0,0 +1,31 @@
+/* eslint-disable camelcase */
+const assert = require('nanoassert')
+const { vn } = require('./crypto_verify')
+
+function sodium_increment (n) {
+  const nlen = n.byteLength
+  var c = 1
+  for (var i = 0; i < nlen; i++) {
+    c += n[i]
+    n[i] = c
+    c >>= 8
+  }
+}
+
+function sodium_memcmp (a, b) {
+  assert(a.byteLength === b.byteLength, 'buffers must be the same size')
+
+  return vn(a, 0, b, 0, a.byteLength) === 0
+}
+
+function sodium_is_zero (arr) {
+  var d = 0
+  for (let i = 0; i < arr.length; i++) d |= arr[i]
+  return d === 0
+}
+
+module.exports = {
+  sodium_increment,
+  sodium_memcmp,
+  sodium_is_zero
+}
diff --git a/index.js b/index.js
index 717ce28..48a88bb 100644
--- a/index.js
+++ b/index.js
@@ -8,7 +8,10 @@
 // Implementation derived from TweetNaCl version 20140427.
 // See for details: http://tweetnacl.cr.yp.to/
 
+forward(require('./randombytes'))
 forward(require('./memory'))
+forward(require('./helpers'))
+forward(require('./crypto_verify'))
 forward(require('./crypto_box'))
 forward(require('./crypto_generichash'))
 forward(require('./crypto_hash'))
@@ -23,8 +26,6 @@ forward(require('./crypto_shorthash'))
 forward(require('./crypto_sign'))
 forward(require('./crypto_stream'))
 forward(require('./crypto_stream_chacha20'))
-forward(require('./crypto_verify'))
-forward(require('./randombytes'))
 
 function forward (submodule) {
   Object.keys(submodule).forEach(function (prop) {
diff --git a/memory.js b/memory.js
index e641d6b..4d8aa4f 100644
--- a/memory.js
+++ b/memory.js
@@ -1,14 +1,23 @@
 /* eslint-disable camelcase */
+var MessageChannel = global.MessageChannel
+if (MessageChannel == null) ({ MessageChannel } = require('worker' + '_threads'))
 
 function sodium_malloc (n) {
   return new Uint8Array(n)
 }
 
+const sink = new MessageChannel()
+function sodium_free (n) {
+  sodium_memzero(n)
+  sink.port1.postMessage(n.buffer, [n.buffer])
+}
+
 function sodium_memzero (arr) {
   arr.fill(0)
 }
 
 module.exports = {
   sodium_malloc,
+  sodium_free,
   sodium_memzero
 }
diff --git a/package.json b/package.json
index b009ca4..8f812da 100644
--- a/package.json
+++ b/package.json
@@ -13,7 +13,6 @@
     "xsalsa20": "^1.0.0"
   },
   "devDependencies": {
-    "browser-run": "^7.0.2",
     "browserify": "^16.5.1",
     "sodium-test": "^0.9.0",
     "standard": "^14.3.4",
@@ -31,10 +30,9 @@
     "crypto": "crypto"
   },
   "scripts": {
-    "browser": "browserify test.js | browser-run",
-    "browser-manual": "browserify test.js | tape-run",
     "pretest": "standard",
-    "test": "node test.js"
+    "test": "node test.js",
+    "test-browser": "browserify test.js | tape-run"
   },
   "repository": {
     "type": "git",