diff --git a/demo/index.html b/demo/index.html
index 264e50ae..cbcc8043 100644
--- a/demo/index.html
+++ b/demo/index.html
@@ -22,6 +22,7 @@
         <script src="/zmodemjs/zsubpacket.js"></script>
         <script src="/zmodemjs/zsession.js"></script>
         <script src="/zmodemjs/zsentry.js"></script>
+        <script src="/zmodemjs/zerror.js"></script>
         <script src="/zmodemjs/zbrowser.js"></script>
     </head>
     <body>
@@ -56,6 +57,7 @@
 
     <form id="zm_progress" style="display: none" action="javascript:void(0)">
         <div><span id="percent_received"></span>% (<span id="bytes_received"></span> bytes) received</div>
+        <button type="button" onclick="abort_current_session(); this.form.style.display='none';">Abort ZMODEM</button>
     </form>
 
     <form id="zm_choose" style="display: none" action="javascript:void(0)">
diff --git a/demo/main.js b/demo/main.js
index 9fcdbda2..f67c66d8 100644
--- a/demo/main.js
+++ b/demo/main.js
@@ -137,7 +137,7 @@ function _hide_file_info() {
     document.getElementById("zm_file").style.display = "none";
 }
 
-function _download(xfer, buffer) {
+function _save_to_disk(xfer, buffer) {
     return Zmodem.Browser.save_to_disk(buffer, xfer.get_details().name);
 }
 
@@ -175,10 +175,12 @@ function _handle_receive_session(zsession) {
                 var FILE_BUFFER = [];
                 xfer.on("input", (payload) => {
                     _update_progress(xfer);
-                    FILE_BUFFER.push.apply(FILE_BUFFER, payload);
+                    FILE_BUFFER.push( new Uint8Array(payload) );
                 });
-                xfer.accept().then( () => {
-                    _download(xfer, FILE_BUFFER);
+                xfer.accept().then(
+                    () => { _save_to_disk(xfer, FILE_BUFFER); },
+                    console.error.bind(console)
+                ).then( () => {
                     _hide_file_info();
                     _hide_progress();
                 } );
@@ -224,6 +226,13 @@ function _handle_send_session(zsession) {
     };
 }
 
+//This is here to allow canceling of an in-progress ZMODEM transfer.
+var current_zsession;
+
+function abort_current_session() {
+    current_zsession.abort();
+}
+
 var text_encoder = new TextEncoder();
 var zsentry = new Zmodem.Sentry( {
     to_terminal(octets) {
@@ -249,6 +258,8 @@ var zsentry = new Zmodem.Sentry( {
             if (e.currentTarget.zmstart.value) {
                 let zsession = detection.confirm();
 
+                current_zsession = zsession;
+
                 if (zsession.type === "receive") {
                     _handle_receive_session(zsession);
                 }
diff --git a/demo/zmodemjs b/demo/zmodemjs
index 46c04daf..58be89b5 160000
--- a/demo/zmodemjs
+++ b/demo/zmodemjs
@@ -1 +1 @@
-Subproject commit 46c04daf223891ed850ef8cdb8327812df9c7a57
+Subproject commit 58be89b58077fe66c07194b4af6997ae2333a725
