diff --git a/mode/tt.py b/mode/tt.py
index c27e516..88be09f 100644
--- a/mode/tt.py
+++ b/mode/tt.py
@@ -35,7 +35,7 @@ class CDataGrammar(Grammar):
 class MetadataGrammar(Grammar):
     rules = [crule, drule, prule] + mode.html.MetadataGrammar.rules
 class DoctypeGrammar(Grammar):
-    rules = [crule, drule, prule] + mode.html.MetadataGrammar.rules
+    rules = [crule, drule, prule] + mode.html.DoctypeGrammar.rules
 
 class TemplateGrammar(Grammar):
     rules = [