diff --git a/src/cleartext.js b/src/cleartext.js
index 5ed0c6a3..94b56eb3 100644
--- a/src/cleartext.js
+++ b/src/cleartext.js
@@ -67,9 +67,10 @@ CleartextMessage.prototype.getSigningKeyIds = function() {
 /**
  * Sign the cleartext message
  * @param  {Array<module:key~Key>} privateKeys private keys with decrypted secret key data for signing
+ * @return {module:message~CleartextMessage} new cleartext message with signed content
  */
 CleartextMessage.prototype.sign = function(privateKeys) {
-  this.signature = this.signDetached(privateKeys);
+  return new CleartextMessage(this.text, this.signDetached(privateKeys));
 };
 
 /**
diff --git a/src/openpgp.js b/src/openpgp.js
index d523d5d4..5a2a5e5a 100644
--- a/src/openpgp.js
+++ b/src/openpgp.js
@@ -273,7 +273,7 @@ export function decrypt({ message, privateKey, publicKeys, sessionKey, password,
 
 /**
  * Signs a cleartext message.
- * @param  {String} data                        cleartext input to be signed
+ * @param  {String | Uint8Array} data           cleartext input to be signed
  * @param  {Key|Array<Key>} privateKeys         array of keys or single key with decrypted secret key data to sign cleartext
  * @param  {Boolean} armor                      (optional) if the return value should be ascii armored or the message object
  * @param  {Boolean} detached                   (optional) if the return value should contain a detached signature
@@ -283,7 +283,7 @@ export function decrypt({ message, privateKey, publicKeys, sessionKey, password,
  * @static
  */
 export function sign({ data, privateKeys, armor=true, detached=false}) {
-  checkString(data);
+  checkData(data);
   privateKeys = toArray(privateKeys);
 
   if (asyncProxy) { // use web worker if available
@@ -292,24 +292,29 @@ export function sign({ data, privateKeys, armor=true, detached=false}) {
 
   var result = {};
   return execute(() => {
+    var message;
 
-    const cleartextMessage = new cleartext.CleartextMessage(data);
+    if (util.isString(data)) {
+      message = new cleartext.CleartextMessage(data);
+    } else {
+      message = messageLib.fromBinary(data);
+    }
 
     if (detached) {
-      var signature = cleartextMessage.signDetached(privateKeys);
+      var signature = message.signDetached(privateKeys);
       if (armor) {
         result.signature = signature.armor();
       } else {
         result.signature = signature;
       }
     } else {
-      cleartextMessage.sign(privateKeys);
+      message = message.sign(privateKeys);
     }
 
     if (armor) {
-      result.data = cleartextMessage.armor();
+      result.data = message.armor();
     } else {
-      result.message = cleartextMessage;
+      result.message = message;
     }
     return result;
 
@@ -326,7 +331,7 @@ export function sign({ data, privateKeys, armor=true, detached=false}) {
  * @static
  */
 export function verify({ message, publicKeys, signature=null }) {
-  checkCleartextMessage(message);
+  checkCleartextOrMessage(message);
   publicKeys = toArray(publicKeys);
 
   if (asyncProxy) { // use web worker if available
@@ -335,8 +340,11 @@ export function verify({ message, publicKeys, signature=null }) {
 
   var result = {};
   return execute(() => {
-    result.data = message.getText();
-
+    if (cleartext.CleartextMessage.prototype.isPrototypeOf(message)) {
+      result.data = message.getText();
+    } else {
+      result.data = message.getLiteralData();
+    }
     if (signature) {
       //detached signature
       result.signatures = message.verifyDetached(signature, publicKeys);
@@ -367,7 +375,7 @@ export function verify({ message, publicKeys, signature=null }) {
  * @static
  */
 export function encryptSessionKey({ data, algorithm, publicKeys, passwords }) {
-  checkbinary(data); checkString(algorithm, 'algorithm'); publicKeys = toArray(publicKeys); passwords = toArray(passwords);
+  checkBinary(data); checkString(algorithm, 'algorithm'); publicKeys = toArray(publicKeys); passwords = toArray(passwords);
 
   if (asyncProxy) { // use web worker if available
     return asyncProxy.delegate('encryptSessionKey', { data, algorithm, publicKeys, passwords });
@@ -417,7 +425,7 @@ function checkString(data, name) {
     throw new Error('Parameter [' + (name || 'data') + '] must be of type String');
   }
 }
-function checkbinary(data, name) {
+function checkBinary(data, name) {
   if (!util.isUint8Array(data)) {
     throw new Error('Parameter [' + (name || 'data') + '] must be of type Uint8Array');
   }
@@ -432,9 +440,9 @@ function checkMessage(message) {
     throw new Error('Parameter [message] needs to be of type Message');
   }
 }
-function checkCleartextMessage(message) {
-  if (!cleartext.CleartextMessage.prototype.isPrototypeOf(message)) {
-    throw new Error('Parameter [message] needs to be of type CleartextMessage');
+function checkCleartextOrMessage(message) {
+  if (!cleartext.CleartextMessage.prototype.isPrototypeOf(message) && !messageLib.Message.prototype.isPrototypeOf(message)) {
+    throw new Error('Parameter [message] needs to be of type Message or CleartextMessage');
   }
 }
 
diff --git a/src/packet/signature.js b/src/packet/signature.js
index f8639894..25e545c9 100644
--- a/src/packet/signature.js
+++ b/src/packet/signature.js
@@ -226,7 +226,7 @@ Signature.prototype.sign = function (key, data) {
 
   var trailer = this.calculateTrailer();
 
-  var toHash = null
+  var toHash = null;
 
   switch (this.version) {
     case 3:
diff --git a/test/general/signature.js b/test/general/signature.js
index dacc59da..254ce574 100644
--- a/test/general/signature.js
+++ b/test/general/signature.js
@@ -527,7 +527,7 @@ describe("Signature", function() {
     });
   });
 
-  it('Sign text with openpgp.sign and verify with openpgp.verify leads to same cleartext and valid signatures', function(done) {
+  it('Sign text with openpgp.sign and verify with openpgp.verify leads to same string cleartext and valid signatures', function(done) {
     var plaintext = 'short message\nnext line\n한국어/조선말';
     var pubKey = openpgp.key.readArmored(pub_key_arm2).keys[0];
     var privKey = openpgp.key.readArmored(priv_key_arm2).keys[0];
@@ -549,6 +549,50 @@ describe("Signature", function() {
 
   });
 
+  it('Sign text with openpgp.sign and verify with openpgp.verify leads to same bytes cleartext and valid signatures - armored', function(done) {
+    var plaintext = openpgp.util.str2Uint8Array('short message\nnext line\n한국어/조선말');
+    var pubKey = openpgp.key.readArmored(pub_key_arm2).keys[0];
+    var privKey = openpgp.key.readArmored(priv_key_arm2).keys[0];
+    privKey.getSigningKeyPacket().decrypt('hello world');
+    console.log(pubKey.armor());
+
+    openpgp.sign({ privateKeys:[privKey], data:plaintext }).then(function(signed) {
+      console.log(signed.data);
+      var csMsg = openpgp.message.readArmored(signed.data);
+      return openpgp.verify({ publicKeys:[pubKey], message:csMsg });
+
+    }).then(function(cleartextSig) {
+      expect(cleartextSig).to.exist;
+      expect(cleartextSig.data).to.deep.equal(plaintext);
+      expect(cleartextSig.signatures).to.have.length(1);
+      expect(cleartextSig.signatures[0].valid).to.be.true;
+      expect(cleartextSig.signatures[0].signature.packets.length).to.equal(1);
+      done();
+    });
+
+  });
+
+  it('Sign text with openpgp.sign and verify with openpgp.verify leads to same bytes cleartext and valid signatures - not armored', function(done) {
+    var plaintext = openpgp.util.str2Uint8Array('short message\nnext line\n한국어/조선말');
+    var pubKey = openpgp.key.readArmored(pub_key_arm2).keys[0];
+    var privKey = openpgp.key.readArmored(priv_key_arm2).keys[0];
+    privKey.getSigningKeyPacket().decrypt('hello world');
+
+    openpgp.sign({ privateKeys:[privKey], data:plaintext, armor:false }).then(function(signed) {
+      var csMsg = signed.message;
+      return openpgp.verify({ publicKeys:[pubKey], message:csMsg });
+
+    }).then(function(cleartextSig) {
+      expect(cleartextSig).to.exist;
+      expect(cleartextSig.data).to.deep.equal(plaintext);
+      expect(cleartextSig.signatures).to.have.length(1);
+      expect(cleartextSig.signatures[0].valid).to.be.true;
+      expect(cleartextSig.signatures[0].signature.packets.length).to.equal(1);
+      done();
+    });
+
+  });
+
   it('Verify primary key revocation signature', function(done) {
     var pubKey = openpgp.key.readArmored(pub_revoked).keys[0];