Index: configure.ac
==================================================================
--- configure.ac
+++ configure.ac
@@ -572,11 +572,11 @@
 		AC_CHECK_FUNC(sched_yield, [
 			AC_DEFINE(OF_HAVE_SCHED_YIELD, 1,
 				[Whether we have sched_yield()])
 		])
 
-		AC_CHECK_HEADERS(pthread_np.h)
+		AC_CHECK_HEADERS(pthread_np.h, [], [], [#include <pthread.h>])
 		AC_CHECK_FUNCS(pthread_set_name_np pthread_setname_np, break)
 		;;
 	esac
 
 	AC_DEFINE(OF_HAVE_THREADS, 1, [Whether we have threads])