diff --git a/blocklist.txt b/blocklist.txt
new file mode 100644
index 0000000..78df532
--- /dev/null
+++ b/blocklist.txt
@@ -0,0 +1,3 @@
+# Stop Firefox from enabeling DoH. Since we are running an ad-blocking DNS 
+# Server we want to use it.
+use-application-dns.net
diff --git a/update-zonefile.py b/update-zonefile.py
index 783e17f..915e9e6 100755
--- a/update-zonefile.py
+++ b/update-zonefile.py
@@ -51,6 +51,7 @@
 regex_no_comment = '^#.*|^$'
 
 lists = [
+    {'file': 'blocklist.txt', 'filter': regex_no_comment},
     {'url': 'https://pgl.yoyo.org/as/serverlist.php?hostformat=nohtml&showintro=0', 'filter': regex_no_comment},
     {'url': 'http://mirror1.malwaredomains.com/files/justdomains', 'filter': regex_no_comment},
     {'url': 'http://winhelp2002.mvps.org/hosts.txt', 'regex': regex_domain, 'filter': regex_no_comment},