diff --git a/extension.js b/extension.js
index edf3de6..64af7b6 100644
--- a/extension.js
+++ b/extension.js
@@ -26,6 +26,9 @@ const Me = imports.misc.extensionUtils.getCurrentExtension();
 const TorButton = Me.imports.ui.tor_button.TorButton;
 const TorControlClient = Me.imports.tor_control_client.TorControlClient;
 
+const TOR_CONTROL_HOST = '127.0.0.1';
+const TOR_CONTROL_PORT = 9051;
+
 let torButton = null;
 let torControlClient = null;
 
@@ -35,7 +38,7 @@ function init(extensionMeta) {
 }
 
 function enable() {
-    torControlClient = new TorControlClient('127.0.0.1', 9051);
+    torControlClient = new TorControlClient(TOR_CONTROL_HOST, TOR_CONTROL_PORT);
     torButton = new TorButton(torControlClient);
     Main.panel.addToStatusArea(torButton.Name, torButton);
     torControlClient.openConnection();
diff --git a/tor_control_client.js b/tor_control_client.js
index 64f03da..760a214 100644
--- a/tor_control_client.js
+++ b/tor_control_client.js
@@ -166,8 +166,11 @@ const TorControlClient = new Lang.Class({
 
         do {
             let line = this._readLine();
-            var reply = this._parseLine(line);
 
+            if (line === null)
+                return {replyLines: ['Lost connection to Tor server']};
+
+            var reply = this._parseLine(line);
             statusCode = reply.statusCode;
             replyLines.push(reply.replyLine);
         } while (reply.isMidReplyLine);
@@ -180,7 +183,8 @@ const TorControlClient = new Lang.Class({
 
     _readLine: function() {
         [line, length] = this._inputStream.read_line(null, null);
-        return line.toString().trim();
+
+        return (line !== null) ? line.toString().trim() : null;
     },
 
     _parseLine: function(line) {
diff --git a/ui/tor_button.js b/ui/tor_button.js
index 5b6ee92..4ddca96 100644
--- a/ui/tor_button.js
+++ b/ui/tor_button.js
@@ -64,7 +64,7 @@ const TorButton = new Lang.Class({
         this._torControlClient.connect('protocol-error', Lang.bind(this, this._onProtocolError));
     },
 
-    _onChangedConnectionState: function(source, state, message, reason) {
+    _onChangedConnectionState: function(source, state, reason) {
         switch (state) {
             case 'ready':
                 this._showConnectedMenu();