diff --git a/4chan_x.js b/4chan_x.js
index a1a8841f6..48e6dfe29 100644
--- a/4chan_x.js
+++ b/4chan_x.js
@@ -1141,7 +1141,7 @@
     dialog: function(link) {
       var MAX_FILE_SIZE, THREAD_ID, challenge, dialog, html, mail, name, pass, spoiler, src;
       MAX_FILE_SIZE = $('input[name="MAX_FILE_SIZE"]').value;
-      THREAD_ID = g.THREAD_ID || link.pathname.split('/').pop();
+      THREAD_ID = g.THREAD_ID || $.x('ancestor::div[@class="thread"]/div', link).id;
       challenge = $('input[name=recaptcha_challenge_field]').value;
       src = "http://www.google.com/recaptcha/api/image?c=" + challenge;
       name = $('input[name=name]').value;
diff --git a/script.coffee b/script.coffee
index 3c2f2330f..4da2cbb1e 100644
--- a/script.coffee
+++ b/script.coffee
@@ -897,8 +897,8 @@ qr =
   dialog: (link) ->
     #maybe should be global
     MAX_FILE_SIZE = $('input[name="MAX_FILE_SIZE"]').value
-    #FIXME inlined quotes
-    THREAD_ID = g.THREAD_ID or link.pathname.split('/').pop()
+    #FIXME inlined cross-thread quotes
+    THREAD_ID = g.THREAD_ID or $.x('ancestor::div[@class="thread"]/div', link).id
     challenge = $('input[name=recaptcha_challenge_field]').value
     src = "http://www.google.com/recaptcha/api/image?c=#{challenge}"
     name = $('input[name=name]').value