diff --git a/misc/yosysjs/yosysjs.js b/misc/yosysjs/yosysjs.js
index eabc0ec50..ea98c9b51 100644
--- a/misc/yosysjs/yosysjs.js
+++ b/misc/yosysjs/yosysjs.js
@@ -224,7 +224,7 @@ var YosysJS = new function() {
 	this.create_worker = function(on_ready) {
 		var ys = new Object();
 		ys.YosysJS = this;
-		ys.worker = new Worker('yosyswrk.js');
+		ys.worker = new Worker(this.url_prefix + 'yosyswrk.js');
 		ys.callback_idx = 1;
 		ys.callback_cache = {};
 		ys.errmsg = "";