diff --git a/src/crypto/random.js b/src/crypto/random.js
index be38c81d..1eab0a44 100644
--- a/src/crypto/random.js
+++ b/src/crypto/random.js
@@ -76,6 +76,9 @@ module.exports = {
    * @param {Uint8Array} buf
    */
   getRandomValues: function(buf) {
+    if (!(buf instanceof Uint8Array)) {
+      throw new Error('Invalid type: buf not an Uint8Array');
+    }
     if (typeof window !== 'undefined' && window.crypto) {
       window.crypto.getRandomValues(buf);
     } else if (nodeCrypto) {
@@ -142,18 +145,21 @@ function RandomBuffer() {
  * @param  {Integer} size size of buffer
  */
 RandomBuffer.prototype.init = function(size) {
-  this.buffer = new Uint32Array(size);
+  this.buffer = new Uint8Array(size);
   this.size = 0;
 };
 
 /**
  * Concat array of secure random numbers to buffer
- * @param {Uint32Array} buf
+ * @param {Uint8Array} buf
  */
 RandomBuffer.prototype.set = function(buf) {
   if (!this.buffer) {
     throw new Error('RandomBuffer is not initialized');
   }
+  if (!(buf instanceof Uint8Array)) {
+    throw new Error('Invalid type: buf not an Uint8Array');
+  }
   var freeSpace = this.buffer.length - this.size;
   if (buf.length > freeSpace) {
     buf = buf.subarray(0, freeSpace);
@@ -164,12 +170,15 @@ RandomBuffer.prototype.set = function(buf) {
 
 /**
  * Take numbers out of buffer and copy to array
- * @param {Uint32Array} buf the destination array
+ * @param {Uint8Array} buf the destination array
  */
 RandomBuffer.prototype.get = function(buf) {
   if (!this.buffer) {
     throw new Error('RandomBuffer is not initialized');
   }
+  if (!(buf instanceof Uint8Array)) {
+    throw new Error('Invalid type: buf not an Uint8Array');
+  }
   if (this.size < buf.length) {
     throw new Error('Random number buffer depleted.')
   }
diff --git a/src/worker/worker.js b/src/worker/worker.js
index f3180251..68e7d628 100644
--- a/src/worker/worker.js
+++ b/src/worker/worker.js
@@ -31,6 +31,9 @@ onmessage = function (event) {
       correct = false;
   switch (msg.event) {
     case 'seed-random':
+      if (!(msg.buf instanceof Uint8Array)) {
+        msg.buf = new Uint8Array(msg.buf);
+      }
       window.openpgp.crypto.random.randomBuffer.set(msg.buf);
       break;
     case 'encrypt-message':
diff --git a/test/worker/api.js b/test/worker/api.js
index b1d2a352..21a6e3c3 100644
--- a/test/worker/api.js
+++ b/test/worker/api.js
@@ -509,6 +509,8 @@ describe('Random Buffer', function() {
   it('Set Method', function () {
     randomBuffer.init(5);
     var buf = new Uint32Array(2);
+    expect(randomBuffer.set.bind(randomBuffer, buf)).to.throw('Invalid type: buf not an Uint8Array');
+    buf = new Uint8Array(2);
     buf[0] = 1; buf[1] = 2;
     randomBuffer.set(buf);
     expect(equal(randomBuffer.buffer, [1,2,0,0,0])).to.be.true;
@@ -520,7 +522,7 @@ describe('Random Buffer', function() {
     expect(equal(randomBuffer.buffer, [1,2,1,2,1])).to.be.true;
     expect(randomBuffer.size).to.equal(5);
     randomBuffer.init(1);
-    var buf = new Uint32Array(2);
+    buf = new Uint8Array(2);
     buf[0] = 1; buf[1] = 2;
     randomBuffer.set(buf);
     expect(buf).to.to.have.property('0', 1);
@@ -529,10 +531,12 @@ describe('Random Buffer', function() {
 
   it('Get Method', function () {
     randomBuffer.init(5);
-    var buf = new Uint32Array(5);
+    var buf = new Uint8Array(5);
     buf[0] = 1; buf[1] = 2; buf[2] = 5; buf[3] = 7; buf[4] = 8;
     randomBuffer.set(buf);
-    var buf = new Uint32Array(2);
+    buf = new Uint32Array(2);
+    expect(randomBuffer.get.bind(randomBuffer, buf)).to.throw('Invalid type: buf not an Uint8Array');
+    buf = new Uint8Array(2);
     randomBuffer.get(buf);
     expect(equal(randomBuffer.buffer, [1,2,5,7,8])).to.be.true;
     expect(randomBuffer.size).to.equal(3);