Index: main/openmpi_ext/src/MPI_Probe.cc
===================================================================
--- main/openmpi_ext/src/MPI_Probe.cc	(revision 10967)
+++ main/openmpi_ext/src/MPI_Probe.cc	(working copy)
@@ -69,7 +69,11 @@
   octave_value_list results;
   int nargin = args.length ();
   if (nargin != 3)
-    print_usage ();
+    {
+      print_usage ();
+      results = octave_value (-1);
+      return results;
+    }
   else
     {
       if (!simple_type_loaded)