diff --git a/index.html b/index.html
index aed6ace..a7abf04 100644
--- a/index.html
+++ b/index.html
@@ -429,7 +429,7 @@
 
 								<hr>
 
-								<label>Null Data</label> <span class="text-muted text-normal">(40 byte limit)</span>
+								<label>Null Data</label> <span class="text-muted text-normal">(80 byte limit, <i>40 bytes recommended</i>)</span>
 								<p class="checkbox">
 									<label><input type="checkbox" id="opReturn" class="checkbox-inline"> Allow data to be sent within the transaction and stored in the blockchain by using <a href="https://bitcoin.org/en/developer-guide#null-data" target="_"blank">OP_RETURN</a>.</label>
 									<div class="text-muted">When using this option you may enter a hex string or address into the address field on the output tab.</div>
diff --git a/js/coin.js b/js/coin.js
index e83087b..25536d3 100644
--- a/js/coin.js
+++ b/js/coin.js
@@ -796,7 +796,7 @@
 		/* add data to a transaction */
 		r.adddata = function(data){
 			var r = false;
-			if(((data.match(/^[a-f0-9]+$/gi)) && data.length<80) && (data.length%2)==0) {
+			if(((data.match(/^[a-f0-9]+$/gi)) && data.length<160) && (data.length%2)==0) {
 				var s = coinjs.script();
 				s.writeOp(106); // OP_RETURN
 				s.writeBytes(Crypto.util.hexToBytes(data));
diff --git a/js/coinbin.js b/js/coinbin.js
index 1044af0..6e5b5f7 100644
--- a/js/coinbin.js
+++ b/js/coinbin.js
@@ -417,7 +417,7 @@ $(document).ready(function() {
 				tx.addoutput(a, $(".amount",o).val());
 			} else if (((a!="") && ad.version === 42) && $(".amount",o).val()!=""){ // stealth address
 				tx.addstealth(ad, $(".amount",o).val());
-			} else if (((($("#opReturn").is(":checked")) && a.match(/^[a-f0-9]+$/ig)) && a.length<80) && (a.length%2)==0) { // data
+			} else if (((($("#opReturn").is(":checked")) && a.match(/^[a-f0-9]+$/ig)) && a.length<160) && (a.length%2)==0) { // data
 				tx.adddata(a);
 			} else { // neither address nor data
 				$(o).addClass('has-error');
diff --git a/sha1sum b/sha1sum
index 024615e..7a6bb11 100644
--- a/sha1sum
+++ b/sha1sum
@@ -10,8 +10,8 @@ f7c09f2f5a721371e7d478050119f7e2d58e3ef9  ./js/crypto-sha256-hmac.js
 ad038e1f39646b68ae666324ed4c2882a8c42474  ./js/qrcode.js
 64eb4ea5c882f8bce3e1885bf00728455f1c2f4c  ./js/ripemd160.js
 114089ef2a3feb6d4db4f9cabcb186d7750d5884  ./js/sha512.js
-3ff26f7ca616b01742a25f9aa304bdb653ce4a4d  ./js/coin.js
-54d781e1399ca0159ef38c8bbc8cb48b1ed4a324  ./js/coinbin.js
+8c2654113866b4a57fec302665ca2187a3eb7614  ./js/coin.js
+e544bb942aeb35a18a4cd7e0b440e6bba7a8e04f  ./js/coinbin.js
 ae49e56999d82802727455f0ba83b63acd90a22b  ./js/jquery-1.9.1.min.js
 5f570018ed044eafd464f7e0ab1783b966224055  ./LICENCE
 ed29315e0ffb3f14382431f2724235bf67f44eb3  ./css/bootstrap.min.css
@@ -25,4 +25,4 @@ de51a8494180a6db074af2dee2383f0a363c5b08  ./fonts/glyphicons-halflings-regular.s
 278e49a86e634da6f2a02f3b47dd9d2a8f26210f  ./fonts/glyphicons-halflings-regular.woff
 44bc1850f570972267b169ae18f1cb06b611ffa2  ./fonts/glyphicons-halflings-regular.ttf
 fe8d57914bb036ab94e86ec35b2671eeb6d20d0d  ./README.md
-5f14c340ab638b39560e30256ed68818053c0af8  ./index.html
+895bbb24f7c218d4c97fc6df90a7e503ec9cadaf  ./index.html