diff --git a/c/src/libnetworking/ChangeLog b/c/src/libnetworking/ChangeLog
index 3aa837d74c..d472e4ceaf 100644
--- a/c/src/libnetworking/ChangeLog
+++ b/c/src/libnetworking/ChangeLog
@@ -1,3 +1,8 @@
+2005-05-20	Sergei Organov  <osv@topconrd.ru>
+
+	PR 750/networking
+	* pppd/sys-rtems.c: Avoid NULL dereference in wait_input().
+
 2004-04-03	Wilfried Busalski <w.busalski@lancier-monitoring.de>
 
 	PR 599/pppd
diff --git a/c/src/libnetworking/pppd/sys-rtems.c b/c/src/libnetworking/pppd/sys-rtems.c
index 0fc3e139b9..d65c50f547 100644
--- a/c/src/libnetworking/pppd/sys-rtems.c
+++ b/c/src/libnetworking/pppd/sys-rtems.c
@@ -513,13 +513,21 @@ void
 wait_input(timo)
     struct timeval *timo;
 {
-  rtems_interval     ticks;
   rtems_event_set    events;
+  rtems_interval     ticks = 0;
+  rtems_option       wait = RTEMS_WAIT;
 
-  ticks = ((timo->tv_sec*1000000)+timo->tv_usec)/rtems_bsdnet_microseconds_per_tick;
-  if ( ticks > 0 ) {
-    rtems_event_receive(RTEMS_EVENT_31, (RTEMS_EVENT_ANY|RTEMS_WAIT), ticks, &events);
+  if(timo) {
+    if(timo->tv_sec == 0 && timo->tv_usec == 0)
+      wait = RTEMS_NO_WAIT;
+    else {
+      ticks = (timo->tv_sec * 1000000 + timo->tv_usec) /
+        rtems_bsdnet_microseconds_per_tick;
+      if(ticks <= 0)
+        ticks = 1;
+    }
   }
+  rtems_event_receive(RTEMS_EVENT_31, RTEMS_EVENT_ANY | wait, ticks, &events);
 }
 
 /*