diff --git a/lib/libc/net/if_indextoname.3 b/lib/libc/net/if_indextoname.3
index 186ddba80faf..0906ee01f749 100644
--- a/lib/libc/net/if_indextoname.3
+++ b/lib/libc/net/if_indextoname.3
@@ -42,6 +42,8 @@
 .Nm if_freenameindex
 .Nd convert interface index to name, and vice versa
 .Sh SYNOPSIS
+.Fd #include <sys/types.h>
+.Fd #include <sys/socket.h>
 .Fd #include <net/if.h>
 .Ft "unsigned int"
 .Fn if_nametoindex "const char *ifname"