diff --git a/extensions/irc/xul/content/handlers.js b/extensions/irc/xul/content/handlers.js
index 3d89618e6695..07359e512f1c 100644
--- a/extensions/irc/xul/content/handlers.js
+++ b/extensions/irc/xul/content/handlers.js
@@ -123,9 +123,6 @@ function onClose()
     if ("userClose" in client && client.userClose)
         return true;
 
-    client.userClose = true;
-    display(MSG_CLOSING);
-
     if (!("getConnectionCount" in client) ||
         client.getConnectionCount() == 0)
     {
@@ -134,7 +131,23 @@ function onClose()
     }
 
     /* otherwise, try to close out gracefully */
-    client.quit(client.userAgent);
+    var close = true;
+    if (client.prefs["warnOnClose"])
+    {
+        const buttons = ["!yes", "!no"];
+        var checkState = { value: true };
+        var rv = confirmEx(MSG_CONFIRM_QUIT, buttons, 0, MSG_WARN_ON_EXIT,
+                           checkState);
+        close = (rv == 0);
+        client.prefs["warnOnClose"] = checkState.value;
+    }
+
+    if (close)
+    {
+        client.userClose = true;
+        display(MSG_CLOSING);
+        client.quit(client.userAgent);
+    }
     return false;
 }
 
diff --git a/extensions/irc/xul/content/prefs.js b/extensions/irc/xul/content/prefs.js
index 0bab684440b3..f9091a5aacd9 100644
--- a/extensions/irc/xul/content/prefs.js
+++ b/extensions/irc/xul/content/prefs.js
@@ -196,7 +196,8 @@ function initPrefs()
          ["usermode",           "+i",     ".ident"],
          ["userHeader",         true,     "global.header"],
          ["userLog",            false,    "global.log"],
-         ["userMaxLines",       200,      "global.maxLines"]
+         ["userMaxLines",       200,      "global.maxLines"],
+         ["warnOnClose",        true,     "global"]
         ];
 
     client.prefManager.addPrefs(prefs);
diff --git a/extensions/irc/xul/locale/en-US/chatzilla.properties b/extensions/irc/xul/locale/en-US/chatzilla.properties
index 23ac99bb3459..c4bfb980a304 100644
--- a/extensions/irc/xul/locale/en-US/chatzilla.properties
+++ b/extensions/irc/xul/locale/en-US/chatzilla.properties
@@ -942,6 +942,8 @@ msg.tabdnd.drop = Would you like to use the file ``%S'' as your new motif?
 msg.default.status = Welcome to ChatZilla!
 
 msg.closing = Disconnecting from IRC.  Click close again to exit now.
+msg.confirm.quit = You are still connected to some networks, are you sure you want to quit ChatZilla?\nConfirming will close the window, and disconnect from all the networks and channels you're connected to.
+msg.warn.on.exit = Warn me when quitting while still connected
 
 msg.whois.name     = "%S <%S@%S> ``%S''
 msg.whois.channels = "%S: member of %S"
@@ -1270,6 +1272,8 @@ pref.username.label             = Username
 pref.username.help              = Your username is used to construct your "host mask", which is a string representing you, by including your connection's host name and this username. It is sometimes used for setting auto-op, bans, and other things specific to one person.
 pref.usermode.label             = Usermode
 pref.usermode.help              = Your usermode determines how the IRC server treats you (it is a list of letters preceded by "+") - for example, you can get the server to send to message about "behind the scenes"-like things but setting a different usermode. The most common option, "i", makes you not show up as a member of a channel unless the user making the query is already in the channel (it stands for "invisible").
+pref.warnOnClose.label          = Warn me when quitting while still connected
+pref.warnOnClose.help           = When quitting while still connected to networks, a message appears asking you if you are sure you want to quit. Uncheck this to disable it.
 
 # Preference group labels #