diff --git a/test.html b/test.html
index 3bb3d31..9411d9a 100644
--- a/test.html
+++ b/test.html
@@ -42,14 +42,6 @@
 		
 		<script>
 			async function clickBtn() {
-				// Set numbers class
-				if (document.getElementById('numbers').value == 'native') {
-					py.pyRCV2.numbers.set_numclass(py.pyRCV2.numbers.Native);
-				}
-				if (document.getElementById('numbers').value == 'rational') {
-					py.pyRCV2.numbers.set_numclass(py.pyRCV2.numbers.Rational);
-				}
-				
 				// Read BLT file
 				let bltFile = document.getElementById('bltFile').files[0];
 				let text = await bltFile.text();
@@ -206,7 +198,10 @@
 					throw evt;
 				}
 				
-				worker.postMessage(text);
+				worker.postMessage({
+					'numbers': document.getElementById('numbers').value,
+					'data': text
+				});
 			}
 		</script>
 	</body>
diff --git a/worker.js b/worker.js
index 59fd41b..70b3495 100644
--- a/worker.js
+++ b/worker.js
@@ -1,7 +1,18 @@
 importScripts('http://peterolson.github.com/BigRational.js/BigInt_BigRat.min.js', 'bundle.js');
 
-onmessage = function(evt) {
-	let election = py.pyRCV2.blt.readBLT(evt.data);
+function sleep(ms) {
+	return new Promise(resolve => setTimeout(resolve, ms));
+}
+
+onmessage = async function(evt) {
+	if (evt.data.numbers == 'native') {
+		py.pyRCV2.numbers.set_numclass(py.pyRCV2.numbers.Native);
+	}
+	if (evt.data.numbers == 'rational') {
+		py.pyRCV2.numbers.set_numclass(py.pyRCV2.numbers.Rational);
+	}
+	
+	let election = py.pyRCV2.blt.readBLT(evt.data.data);
 	postMessage({'type': 'init', 'election': {
 		'candidates': election.candidates.map(c => c.py_name)
 	}});
@@ -29,6 +40,7 @@ onmessage = function(evt) {
 	
 	// Step election
 	while (true) {
+		//await sleep(1000);
 		result = counter.step();
 		if (py.isinstance(result, py.pyRCV2.model.CountCompleted)) {
 			postMessage({'type': 'done'});