From 0e6e1855319998d97c944bb7d1889b810820cc9b Mon Sep 17 00:00:00 2001
From: Aswin S Vijay <aswinsvijay03052000@gmail.com>
Date: Fri, 1 May 2026 20:03:00 +0000
Subject: [PATCH] fix label names when `internalSignature` has optional params

---
 ark/type/fn.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/ark/type/fn.ts b/ark/type/fn.ts
index 992eee80e8..0633c6fa1b 100644
--- a/ark/type/fn.ts
+++ b/ark/type/fn.ts
@@ -38,7 +38,7 @@ export type BaseFnParser<$ = {}> = <
 	externalSignature extends Fn = (
 		...args: applyElementLabels<
 			distill.In<paramsT>,
-			Parameters<internalSignature>
+			Required<Parameters<internalSignature>>
 		>
 	) => args extends readonly [...unknown[], ":", unknown] ? distill.Out<returnT>
 	:	ReturnType<internalSignature>