Index: sys/netpfil/ipfw/pmod/ip_fw_pmod.c
===================================================================
--- sys/netpfil/ipfw/pmod/ip_fw_pmod.c	(revision 335757)
+++ sys/netpfil/ipfw/pmod/ip_fw_pmod.c	(working copy)
@@ -28,6 +28,12 @@
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
+/*
+ * Manually include opt_global.h to support module build
+ * outside of kernel build environment.
+ */
+#include "opt_global.h"
+
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/kernel.h>
Index: sys/modules/ipfw_pmod/Makefile
===================================================================
--- sys/modules/ipfw_pmod/Makefile	(revision 335757)
+++ sys/modules/ipfw_pmod/Makefile	(working copy)
@@ -3,6 +3,13 @@
 .PATH: ${SRCTOP}/sys/netpfil/ipfw/pmod
 
 KMOD=   ipfw_pmod
-SRCS=   ip_fw_pmod.c tcpmod.c opt_inet.h opt_inet6.h
+SRCS=   ip_fw_pmod.c tcpmod.c opt_global.h opt_inet.h opt_inet6.h
 
+.if !defined(KERNBUILDDIR)
+.if defined(VIMAGE)
+opt_global.h:
+	echo "#define VIMAGE 1" >> ${.TARGET}
+.endif
+.endif
+
 .include <bsd.kmod.mk>