diff --git a/toolkit/devtools/server/main.js b/toolkit/devtools/server/main.js
index 6d7dce7b7221..71638ee5e19d 100644
--- a/toolkit/devtools/server/main.js
+++ b/toolkit/devtools/server/main.js
@@ -150,15 +150,20 @@ var DebuggerServer = {
    * method returns, the debugger server must be initialized again before use.
    */
   destroy: function DS_destroy() {
-    if (Object.keys(this._connections).length == 0) {
-      this.closeListener();
-      this.globalActorFactories = {};
-      this.tabActorFactories = {};
-      delete this._allowConnection;
-      this._transportInitialized = false;
-      this._initialized = false;
-      dumpn("Debugger server is shut down.");
+    if (!this._initialized) {
+      return;
     }
+
+    for (let connID of Object.getOwnPropertyNames(this._connections)) {
+      this._connections[connID].close();
+    }
+    this.closeListener();
+    this.globalActorFactories = {};
+    this.tabActorFactories = {};
+    delete this._allowConnection;
+    this._transportInitialized = false;
+    this._initialized = false;
+    dumpn("Debugger server is shut down.");
   },
 
   /**
@@ -525,6 +530,10 @@ DebuggerServerConnection.prototype = {
   _transport: null,
   get transport() { return this._transport },
 
+  close: function() {
+    this._transport.close();
+  },
+
   send: function DSC_send(aPacket) {
     this.transport.send(aPacket);
   },
diff --git a/toolkit/devtools/server/transport.js b/toolkit/devtools/server/transport.js
index 3a27c0dc7c64..a8a8c444075a 100644
--- a/toolkit/devtools/server/transport.js
+++ b/toolkit/devtools/server/transport.js
@@ -173,7 +173,10 @@ DebuggerTransport.prototype = {
   onStopRequest:
   makeInfallible(function DT_onStopRequest(aRequest, aContext, aStatus) {
     this.close();
-    this.hooks.onClosed(aStatus);
+    if (this.hooks) {
+      this.hooks.onClosed(aStatus);
+      this.hooks = null;
+    }
   }, "DebuggerTransport.prototype.onStopRequest"),
 
   onDataAvailable:
@@ -292,7 +295,10 @@ LocalDebuggerTransport.prototype = {
       delete this.other;
       other.close();
     }
-    this.hooks.onClosed();
+    if (this.hooks) {
+      this.hooks.onClosed();
+      this.hooks = null;
+    }
   },
 
   /**