diff --git a/usr.bin/kdump/Makefile b/usr.bin/kdump/Makefile
index 0af84ccb42d4..afa94bb7d127 100644
--- a/usr.bin/kdump/Makefile
+++ b/usr.bin/kdump/Makefile
@@ -22,7 +22,7 @@ CLEANFILES=	ioctl.c kdump_subr.c kdump_subr.h linux_syscalls.c
 
 ioctl.c: mkioctls
 	env MACHINE=${MACHINE} \
-	    sh ${.CURDIR}/mkioctls ${DESTDIR}/usr/include > ${.TARGET}
+	    sh ${.CURDIR}/mkioctls print ${DESTDIR}/usr/include > ${.TARGET}
 
 kdump_subr.h: mksubr
 	sh ${.CURDIR}/mksubr ${DESTDIR}/usr/include | \
diff --git a/usr.bin/kdump/mkioctls b/usr.bin/kdump/mkioctls
index 7ef2865b26e8..22ca26854dc1 100644
--- a/usr.bin/kdump/mkioctls
+++ b/usr.bin/kdump/mkioctls
@@ -1,20 +1,26 @@
 #!/bin/sh
 #
 # $FreeBSD$
+#
+# When editing this script, keep in mind that truss also uses it.
+#
 
 set -e
 
-if [ -z "$1" ]; then
-	echo "usage: sh $0 include-dir"
+if [ $# -ne 2 -o \( $1 != "print" -a $1 != "return" \) ]; then
+	echo "usage: sh $0 print|return include-dir"
 	exit 1
 fi
 
+style="$1"
+includedir="$2"
+
 LC_ALL=C; export LC_ALL
 
 # Build a list of headers that have ioctls in them.
 # XXX should we use an ANSI cpp?
 ioctl_includes=$(
-	cd $1
+	cd $includedir
 	find -H -s * -name '*.h' | grep -v '.*disk.*\.h' | \
 		xargs egrep -l \
 '^#[ 	]*define[ 	]+[A-Za-z_][A-Za-z0-9_]*[ 	]+_IO[^a-z0-9_]' |
@@ -33,7 +39,7 @@ esac
 
 awk -v x="$ioctl_includes" 'BEGIN {print x}' |
 	gcc -E -I$1 -dM -DCOMPAT_43TTY - |
-	awk -v ioctl_includes="$ioctl_includes" '
+	awk -v ioctl_includes="$ioctl_includes" -v style="$style" '
 BEGIN {
 	print "/* XXX obnoxious prerequisites. */"
 	print "#define COMPAT_43"
@@ -58,12 +64,19 @@ BEGIN {
 	print "#include <stdio.h>"
 	print "#include <cam/cam.h>"
 	print ""
-	print "void ioctlname(unsigned long val, int decimal);"
-	print ""
 	print ioctl_includes
 	print ""
-	print "void"
-	print "ioctlname(unsigned long val, int decimal)"
+	if (style == "print") {
+		print "void ioctlname(unsigned long val, int decimal);"
+		print ""
+		print "void"
+		print "ioctlname(unsigned long val, int decimal)"
+	} else {
+		print "const char *ioctlname(unsigned long val);"
+		print ""
+		print "const char *"
+		print "ioctlname(unsigned long val)"
+	}
 	print "{"
 	print "\tconst char *str = NULL;"
 	print ""
@@ -77,20 +90,24 @@ BEGIN {
 			break;
 	++i;
 	#
-	print("\t");
+	printf("\t");
 	if (n++ > 0)
-		print("else ");
+		printf("else ");
 	printf("if (val == %s)\n", $i);
 	printf("\t\tstr = \"%s\";\n", $i);
 }
 END {
-	print "\n"
-	print "\tif (str != NULL)\n"
-	print "\t\tprintf(\"%s\", str);\n"
-	print "\telse if (decimal)\n"
-	print "\t\tprintf(\"%lu\", val);\n"
-	print "\telse\n"
-	print "\t\tprintf(\"%#lx\", val);\n"
+	print ""
+	if (style == "print") {
+		print "\tif (str != NULL)"
+		print "\t\tprintf(\"%s\", str);"
+		print "\telse if (decimal)"
+		print "\t\tprintf(\"%lu\", val);"
+		print "\telse"
+		print "\t\tprintf(\"%#lx\", val);"
+	} else {
+		print "\treturn (str);"
+	}
 	print "}"
 }
 '
diff --git a/usr.bin/truss/Makefile b/usr.bin/truss/Makefile
index f80ac0367ea6..31f08d49b444 100644
--- a/usr.bin/truss/Makefile
+++ b/usr.bin/truss/Makefile
@@ -23,7 +23,8 @@ syscalls.h:	syscalls.master
 		${.CURDIR}/i386.conf
 
 ioctl.c: ${.CURDIR}/../kdump/mkioctls
-	sh ${.CURDIR}/../kdump/mkioctls ${DESTDIR}/usr/include > ${.TARGET}
+	env MACHINE=${MACHINE} \
+		/bin/sh ${.CURDIR}/../kdump/mkioctls return ${DESTDIR}/usr/include > ${.TARGET}
 
 .if ${MACHINE_CPUARCH} == "i386"
 SRCS+=	i386-linux.c linux_syscalls.h
diff --git a/usr.bin/truss/extern.h b/usr.bin/truss/extern.h
index e3ffc4f566a3..a56a01eb634f 100644
--- a/usr.bin/truss/extern.h
+++ b/usr.bin/truss/extern.h
@@ -35,7 +35,7 @@ extern int setup_and_wait(char **);
 extern int start_tracing(int);
 extern void restore_proc(int);
 extern void waitevent(struct trussinfo *);
-extern const char *ioctlname(register_t val);
+extern const char *ioctlname(unsigned long val);
 extern char *strsig(int sig);
 #ifdef __amd64__
 extern void amd64_syscall_entry(struct trussinfo *, int);