diff --git a/usr.bin/kdump/mkioctls b/usr.bin/kdump/mkioctls
index a68524bf8a6..86f1d88ad5b 100644
--- a/usr.bin/kdump/mkioctls
+++ b/usr.bin/kdump/mkioctls
@@ -42,7 +42,7 @@ BEGIN {
 	print ioctl_includes
 	print ""
 	print "char *"
-	print "ioctlname(u_long val)"
+	print "ioctlname(register_t val)"
 	print "{"
 	print ""
 	generate_case_statement = 0