diff --git a/4chan_x.user.js b/4chan_x.user.js
index 3c0218017..b7ec7269d 100644
--- a/4chan_x.user.js
+++ b/4chan_x.user.js
@@ -1255,6 +1255,7 @@
         }
       });
       QR.accept = "'" + accept + "'";
+      QR.MAX_FILE_SIZE = $('input[name=MAX_FILE_SIZE]').value;
       QR.spoiler = $('.postarea label') ? ' <label>[<input type=checkbox name=spoiler>Spoiler Image?]</label>' : '';
       if (conf['Persistent QR']) {
         QR.dialog();
@@ -1332,8 +1333,13 @@
       return captcha;
     },
     change: function() {
-      $.unbind(this, 'change', QR.change);
-      return QR.attach();
+      if (this.files[0].size > QR.MAX_FILE_SIZE) {
+        alert('Error: File too large.');
+        return this.click();
+      } else {
+        $.unbind(this, 'change', QR.change);
+        return QR.attach();
+      }
     },
     close: function() {
       $.rm(QR.qr);
diff --git a/script.coffee b/script.coffee
index d95bb2357..48785a622 100644
--- a/script.coffee
+++ b/script.coffee
@@ -987,6 +987,7 @@ QR =
         else
           'image/' + type
     QR.accept = "'#{accept}'"
+    QR.MAX_FILE_SIZE = $('input[name=MAX_FILE_SIZE]').value
     QR.spoiler = if $('.postarea label') then ' <label>[<input type=checkbox name=spoiler>Spoiler Image?]</label>' else ''
     if conf['Persistent QR']
       QR.dialog()
@@ -1040,8 +1041,12 @@ QR =
     $('#cl', QR.qr).textContent = captchas.length + ' captchas'
     captcha
   change: ->
-    $.unbind @, 'change', QR.change
-    QR.attach()
+    if @files[0].size > QR.MAX_FILE_SIZE
+      alert 'Error: File too large.'
+      @.click()
+    else
+      $.unbind @, 'change', QR.change
+      QR.attach()
   close: ->
     $.rm QR.qr
     QR.qr = null