diff --git a/keywords.md b/keywords.md
index 8d6104bb671c1..8f1a0479f9d7b 100644
--- a/keywords.md
+++ b/keywords.md
@@ -459,6 +459,7 @@ The following list shows the keywords in TiDB. Reserved keywords are marked with
 - NATIONAL
 - NATURAL (R)
 - NCHAR
+- NDVRATE
 - NEVER
 - NEXT
 - NEXTVAL