diff --git a/Userland/Libraries/LibC/netinet/if_ether.h b/Userland/Libraries/LibC/netinet/if_ether.h
new file mode 100644
index 0000000000..4b0f390c42
--- /dev/null
+++ b/Userland/Libraries/LibC/netinet/if_ether.h
@@ -0,0 +1,9 @@
+/*
+ * Copyright (c) 2021, Idan Horowitz <idan.horowitz@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#define ETH_ALEN 6 // Length of an ethernet address (MAC) in bytes