diff --git a/spec/registry.md b/spec/registry.md
index 2382485836..d2eaa7a8fe 100644
--- a/spec/registry.md
+++ b/spec/registry.md
@@ -281,6 +281,7 @@ function `:integer`:
 - `useGrouping`
   - `auto` (default)
   - `always`
+  - `never`
   - `min2`
 - `minimumIntegerDigits`
   - ([digit size option](#digit-size-options), default: `1`)