diff --git a/firefox/30-auto.yml b/firefox/30-auto.yml
new file mode 100644
index 00000000..50961391
--- /dev/null
+++ b/firefox/30-auto.yml
@@ -0,0 +1,11 @@
+%YAML 1.2
+---
+version: 1.1
+
+auto:
+  description: Automatic proxy configuration URL
+  type: web_address
+  disabled:
+    variable: _.proxy_mode
+    when_not: Automatic proxy configuration URL
+...