diff --git a/Sources/WireGuardKitC/WireGuardKitC.h b/Sources/WireGuardKitC/WireGuardKitC.h
index 36218b9c..3ffb08d5 100644
--- a/Sources/WireGuardKitC/WireGuardKitC.h
+++ b/Sources/WireGuardKitC/WireGuardKitC.h
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: MIT
 // Copyright © 2018-2021 WireGuard LLC. All Rights Reserved.
-
+#include <sys/types.h>
 #include "key.h"
 #include "x25519.h"