diff --git a/keywords.md b/keywords.md
index 54f6b4b86cd15..aa49fc84ea1c1 100644
--- a/keywords.md
+++ b/keywords.md
@@ -450,6 +450,7 @@ The following list shows the keywords in TiDB. Reserved keywords are marked with
 - NATIONAL
 - NATURAL (R)
 - NCHAR
+- NDVRATE
 - NEVER
 - NEXT
 - NEXTVAL