Index: configure.ac
--- configure.ac.orig
+++ configure.ac
@@ -358,6 +358,7 @@ AC_CHECK_HEADERS([netinet/udp.h], [], [],
 
 # For cpu modules
 AC_CHECK_HEADERS([sys/dkstat.h])
+AC_CHECK_HEADERS([sys/sched.h])
 if test "x$ac_system" = "xDarwin"; then
   AC_CHECK_HEADERS(
     [ \