diff --git a/src/packages/collaboration/lib/session-utils.coffee b/src/packages/collaboration/lib/session-utils.coffee
index b7c41c50e..bf5f68654 100644
--- a/src/packages/collaboration/lib/session-utils.coffee
+++ b/src/packages/collaboration/lib/session-utils.coffee
@@ -7,10 +7,14 @@ module.exports =
     new Peer(id, host: 'ec2-54-218-51-127.us-west-2.compute.amazonaws.com', port: 8080)
 
   connectDocument: (doc, connection) ->
-    doc.outputEvents.on 'changed', (event) ->
+    outputListener = (event) ->
       console.log 'sending event', event
       connection.send(event)
+    doc.outputEvents.on('changed', outputListener)
 
     connection.on 'data', (event) ->
       console.log 'receiving event', event
       doc.handleInputEvent(event)
+
+    connection.on 'close', ->
+      doc.outputEvents.removeListener('changed', outputListener)