diff --git a/contrib/js/cuckoo_miner.js b/contrib/js/cuckoo_miner.js
index fee545d..ed7244f 100644
--- a/contrib/js/cuckoo_miner.js
+++ b/contrib/js/cuckoo_miner.js
@@ -1,8 +1,14 @@
 onready(function(){
 	document.getElementById("start_miner").onclick = function() {
+		var btn = document.getElementById("start_miner");
+		var label = btn.value;
+		btn.value = "..."
+		btn.disabled = true;
 		var worker = new Worker("./static/mineworker.js");
 		worker.onmessage = function(e) {
 		  miner_cb(e.data);
+		  btn.value=label;
+		  btn.disabled = false;
 		  worker.terminate();
 		}
 		worker.postMessage(55.0); // Start the worker.
diff --git a/contrib/static/nntpchan.js b/contrib/static/nntpchan.js
index d1acaf7..017995f 100644
--- a/contrib/static/nntpchan.js
+++ b/contrib/static/nntpchan.js
@@ -620,7 +620,8 @@ parent.appendChild(post);}
 /* local file: ./contrib/js/banner.js */
 var banner_count=3;function nntpchan_inject_banners(elem,prefix){var n=Math.floor(Math.random()*banner_count);var banner=prefix+"static/banner_"+n+".jpg";var e=document.createElement("img");e.src=banner;e.id="nntpchan_banner";elem.appendChild(e);}
 /* local file: ./contrib/js/cuckoo_miner.js */
-onready(function(){document.getElementById("start_miner").onclick=function(){var worker=new Worker("./static/mineworker.js");worker.onmessage=function(e){miner_cb(e.data);worker.terminate();}
+onready(function(){document.getElementById("start_miner").onclick=function(){var btn=document.getElementById("start_miner");var label=btn.value;btn.value="..."
+btn.disabled=true;var worker=new Worker("./static/mineworker.js");worker.onmessage=function(e){miner_cb(e.data);btn.value=label;btn.disabled=false;worker.terminate();}
 worker.postMessage(55.0);};});function miner_cb(s){document.getElementById("miner_result").value=s;}
 /* local file: ./contrib/js/expand-image.js */
 function filenameIsImage(fname){return/\.(gif|jpeg|jpg|png|webp)/.test(fname.toLowerCase());}