diff --git a/samples/stdout-helper/src/main/webapp/teavm/stdout.js b/samples/stdout-helper/src/main/webapp/teavm/stdout.js
index 9e1116858..05af1d9d6 100644
--- a/samples/stdout-helper/src/main/webapp/teavm/stdout.js
+++ b/samples/stdout-helper/src/main/webapp/teavm/stdout.js
@@ -1,18 +1,20 @@
 let $rt_stdoutBuffer = "";
-function $rt_putStdoutCustom(str) {
+function $rt_putStdoutCustom(msg) {
     let index = 0;
     while (true) {
         let next = msg.indexOf('\n', index);
         if (next < 0) {
             break;
         }
-        let line = buffer + msg.substring(index, next);
+        let line = $rt_stdoutBuffer + msg.substring(index, next);
         let lineElem = document.createElement("div");
         let stdoutElem = document.getElementById("stdout");
         lineElem.appendChild(document.createTextNode(line));
         stdoutElem.appendChild(lineElem);
-        buffer = "";
+        stdoutElem.scrollTop = stdoutElem.scrollHeight;
+        $rt_stdoutBuffer = "";
         index = next + 1;
     }
+    $rt_stdoutBuffer += msg.substring(index);
 }
 this.$rt_putStdoutCustom = $rt_putStdoutCustom;
\ No newline at end of file