diff --git a/src/openpgp.js b/src/openpgp.js
index b6a4b7d9..4538f982 100644
--- a/src/openpgp.js
+++ b/src/openpgp.js
@@ -59,6 +59,10 @@ function initWorker(path) {
  * @static
  */
 function encryptMessage(keys, text, callback) {
+  if (typeof keys === 'string') {
+    keys = [keys];
+  }
+
   if (useWorker(callback)) {
     asyncProxy.encryptMessage(keys, text, callback);
     return;
@@ -165,6 +169,10 @@ function decryptAndVerifyMessage(privateKey, publicKeys, msg, callback) {
  * @static
  */
 function signClearMessage(privateKeys, text, callback) {
+  if (typeof privateKeys === 'string') {
+    privateKeys = [privateKeys];
+  }
+
   if (useWorker(callback)) {
     asyncProxy.signClearMessage(privateKeys, text, callback);
     return;
diff --git a/src/worker/async_proxy.js b/src/worker/async_proxy.js
index 1d9af298..cfa615b8 100644
--- a/src/worker/async_proxy.js
+++ b/src/worker/async_proxy.js
@@ -101,6 +101,9 @@ AsyncProxy.prototype.terminate = function() {
  * @param  {Function} callback receives encrypted ASCII armored message
  */
 AsyncProxy.prototype.encryptMessage = function(keys, text, callback) {
+  if (typeof keys === 'string') {
+    keys = [keys];
+  }
   keys = keys.map(function(key) {
     return key.toPacketlist();
   });
@@ -193,6 +196,9 @@ AsyncProxy.prototype.decryptAndVerifyMessage = function(privateKey, publicKeys,
  * @param  {Function} callback       receives ASCII armored message
  */
 AsyncProxy.prototype.signClearMessage = function(privateKeys, text, callback) {
+  if (typeof privateKeys === 'string') {
+    privateKeys = [privateKeys];
+  }
   privateKeys = privateKeys.map(function(key) {
     return key.toPacketlist();
   });
diff --git a/src/worker/worker.js b/src/worker/worker.js
index 844072da..b1636e83 100644
--- a/src/worker/worker.js
+++ b/src/worker/worker.js
@@ -38,6 +38,9 @@ onmessage = function (event) {
       break;
     case 'encrypt-message':
       try {
+        if (typeof msg.keys === 'string') {
+          msg.keys = [msg.keys];
+        }
         msg.keys = msg.keys.map(packetlistCloneToKey);
         data = window.openpgp.encryptMessage(msg.keys, msg.text);
       } catch (e) {