diff --git a/usr.sbin/ppp/i4b.c b/usr.sbin/ppp/i4b.c
index 855bfcef89a6..a191bb00f11e 100644
--- a/usr.sbin/ppp/i4b.c
+++ b/usr.sbin/ppp/i4b.c
@@ -39,9 +39,14 @@
 #include <machine/i4b_ioctl.h>
 #include <machine/i4b_rbch_ioctl.h>
 #else
+#ifdef __NetBSD__
+#include <netisdn/i4b_ioctl.h>
+#include <netisdn/i4b_rbch_ioctl.h>
+#else
 #include <i4b/i4b_ioctl.h>
 #include <i4b/i4b_rbch_ioctl.h>
 #endif
+#endif
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>