diff --git a/src/cleanup.js b/src/cleanup.js
index f8695a3..bfc53db 100644
--- a/src/cleanup.js
+++ b/src/cleanup.js
@@ -8,6 +8,7 @@ const validFields = new Set([
   'required',
   'pattern',
   'enum',
+  'const',
   'minimum',
   'maximum',
   'exclusiveMinimum',