--- libelwix/src/pio.c	2015/06/25 17:53:50	1.4
+++ libelwix/src/pio.c	2016/05/18 12:47:42	1.5
@@ -3,7 +3,7 @@
 *  by Michael Pounov <misho@elwix.org>
 *
 * $Author: misho $
-* $Id: pio.c,v 1.4 2015/06/25 17:53:50 misho Exp $
+* $Id: pio.c,v 1.5 2016/05/18 12:47:42 misho Exp $
 *
 **************************************************************************
 The ELWIX and AITNET software is distributed under the following
@@ -49,11 +49,15 @@ SUCH DAMAGE.
 extern char **environ;
 
 pio_pid_t pio_pidlist = SLIST_HEAD_INITIALIZER(pio_pidlist);
+#ifdef HAVE_LIBPTHREAD
 static pthread_mutex_t pidlist_mutex = PTHREAD_MUTEX_INITIALIZER;
 
-#define	THREAD_LOCK()	if (__isthreaded) pthread_mutex_lock(&pidlist_mutex)
-#define	THREAD_UNLOCK()	if (__isthreaded) pthread_mutex_unlock(&pidlist_mutex)
-
+#define	THREAD_LOCK()	pthread_mutex_lock(&pidlist_mutex)
+#define	THREAD_UNLOCK()	pthread_mutex_unlock(&pidlist_mutex)
+#else
+#define	THREAD_LOCK()
+#define	THREAD_UNLOCK()
+#endif
 
 /*
  * e_popen() - ELWIX replacement of standard popen