From 7f8411e83c672f66539e40b7f4bd718a39076577 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Julien=20Valverd=C3=A9?= <julien.valverde@mailo.com>
Date: Mon, 23 Mar 2026 20:15:43 +0100
Subject: [PATCH] Fix

---
 packages/effect-fc/src/Lens.ts | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/packages/effect-fc/src/Lens.ts b/packages/effect-fc/src/Lens.ts
index 6c7da97..b0a1dcd 100644
--- a/packages/effect-fc/src/Lens.ts
+++ b/packages/effect-fc/src/Lens.ts
@@ -79,7 +79,9 @@ export const map = <A, ER, RR, EW, RW, B>(
         (b: B): (parent: A) => A
     },
 ): Lens<B, ER, RR, EW, RW> => {
-    const setF =
+    const setF = (parent: A, b: B) => set.length >= 2
+        ? (set as (parent: A, b: B) => A)(parent, b)
+        : (set as (b: B) => (parent: A) => A)(b)(parent)
 
     return make({
         get: Effect.map(self.get, get),
@@ -87,7 +89,7 @@ export const map = <A, ER, RR, EW, RW, B>(
         modify: <C, E1 = never, R1 = never>(
             f: (b: B) => Effect.Effect<readonly [C, B], E1, R1>
         ) => self.modify((a: A) =>
-            Effect.flatMap(f(get(a)), ([c, next]) => Effect.succeed([c, set(a, next)] as const))
+            Effect.flatMap(f(get(a)), ([c, next]) => Effect.succeed([c, setF(a, next)] as const))
         ),
     })
 }