diff --git a/ptml/ptml.g4 b/ptml/ptml.g4
index 2724e62..e148145 100644
--- a/ptml/ptml.g4
+++ b/ptml/ptml.g4
@@ -1,3 +1,3 @@
 grammar ptml;
 
-tree :
\ No newline at end of file
+tree : t
\ No newline at end of file