diff --git a/lib/rules/subsystem.js b/lib/rules/subsystem.js
index 611765d..12c1961 100644
--- a/lib/rules/subsystem.js
+++ b/lib/rules/subsystem.js
@@ -45,6 +45,7 @@ const validSubsystems = [
   'diagnostics_channel',
   'dns',
   'domain',
+  'dtls',
   'events',
   'fs',
   'http',