diff --git a/Sources/WireGuardKitC/WireGuardKitC.h b/Sources/WireGuardKitC/WireGuardKitC.h
index 54e4783..22d5d64 100644
--- a/Sources/WireGuardKitC/WireGuardKitC.h
+++ b/Sources/WireGuardKitC/WireGuardKitC.h
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: MIT
 // Copyright © 2018-2023 WireGuard LLC. All Rights Reserved.
 
+#include <Foundation/Foundation.h>
 #include "key.h"
 #include "x25519.h"