diff --git a/etc/firefox/policies/policies.json b/etc/firefox/policies/policies.json
index 118b33fa..f068f252 100644
--- a/etc/firefox/policies/policies.json
+++ b/etc/firefox/policies/policies.json
@@ -69,7 +69,7 @@
     },
     "DNSOverHTTPS": {
       "Enabled": true,
-      "Locked": false,
+      "Locked": true,
       "ProviderURL": "https://dns11.quad9.net/dns-query"
     },
     "DisableEncryptedClientHello": false,