diff --git a/cpukit/rtems/ChangeLog b/cpukit/rtems/ChangeLog
index f6903001e7..5cc3cf69a5 100644
--- a/cpukit/rtems/ChangeLog
+++ b/cpukit/rtems/ChangeLog
@@ -1,3 +1,9 @@
+2004-07-24	Joel Sherrill <joel@OARcorp.com>
+
+	PR rtems/652
+	* src/signalsend.c: Return RTEMS_INVALID_NUMBER when sending an empty
+	signal set.
+
 2004-07-14	Joel Sherrill <joel@OARcorp.com>
 
 	PR 651/core
diff --git a/cpukit/rtems/src/signalsend.c b/cpukit/rtems/src/signalsend.c
index e5d512bcc2..e5c801bdc1 100644
--- a/cpukit/rtems/src/signalsend.c
+++ b/cpukit/rtems/src/signalsend.c
@@ -33,12 +33,12 @@
  *
  *  Output parameters:
  *    RTEMS_SUCCESSFUL - if successful
- *    error code - if unsuccessful
+ *    error code       - if unsuccessful
  */
 
 rtems_status_code rtems_signal_send(
-  Objects_Id             id,
-  rtems_signal_set signal_set
+  Objects_Id        id,
+  rtems_signal_set  signal_set
 )
 {
   register Thread_Control *the_thread;
@@ -46,6 +46,9 @@ rtems_status_code rtems_signal_send(
   RTEMS_API_Control       *api;
   ASR_Information         *asr;
 
+  if ( !signal_set )
+    return RTEMS_INVALID_NUMBER;
+
   the_thread = _Thread_Get( id, &location );
   switch ( location ) {