diff --git a/whalesong/repl-prototype/htdocs/index.html b/whalesong/repl-prototype/htdocs/index.html
index 89259f2..2133991 100644
--- a/whalesong/repl-prototype/htdocs/index.html
+++ b/whalesong/repl-prototype/htdocs/index.html
@@ -8,7 +8,7 @@
 <body>
 <h1>Repl experiment</h1>
 
-<div id="output"></div>
+<div id="output" style="width:500px; height:300px; border:1px solid black; overflow:scroll"></div>
 <br/>
 <input id="repl" type="text" style="width:500px"></input><img id="break" src="break.png"/>
 </body>
diff --git a/whalesong/repl-prototype/htdocs/repl.js b/whalesong/repl-prototype/htdocs/repl.js
index 3fb615a..67ea19e 100644
--- a/whalesong/repl-prototype/htdocs/repl.js
+++ b/whalesong/repl-prototype/htdocs/repl.js
@@ -15,10 +15,12 @@ $(document).ready(function() {
     // We configure output to send it to the "output" DOM node.
     M.params.currentDisplayer = function(MACHINE, domNode) {
         $(domNode).appendTo(output);
-    }
+        output.get(0).scrollTop = output.get(0).scrollHeight;
+    };
     M.params.currentErrorDisplayer = function(MACHINE, domNode) {
         $(domNode).css("color", "red").appendTo(output);
-    }
+        output.get(0).scrollTop = output.get(0).scrollHeight;
+    };
 
 
     // We then want to initialize the language module.
