diff --git a/double_pinyin_mspy.schema.yaml b/double_pinyin_mspy.schema.yaml
index 76a2826..ae6cf18 100644
--- a/double_pinyin_mspy.schema.yaml
+++ b/double_pinyin_mspy.schema.yaml
@@ -262,7 +262,7 @@ speller:
     - xform/(.)ei$/$1Ⓩ/
     - xform/ie$/Ⓧ/
     - xform/ui$/Ⓥ/
-    - derive/T$/Ⓥ/
+    - derive/Ⓣ$/Ⓥ/
     - xform/(.)ou$/$1Ⓑ/
     - xform/in$/Ⓝ/
     - xform/ing$/;/