diff --git a/LAXlib/mp_diag.f90 b/LAXlib/mp_diag.f90
index dc8293f9e..6be9cd848 100644
--- a/LAXlib/mp_diag.f90
+++ b/LAXlib/mp_diag.f90
@@ -98,7 +98,7 @@ CONTAINS
        ! no command-line argument -ndiag N or -northo N is present
        ! insert here custom architecture specific default definitions
 #if defined __SCALAPACK
-       nproc_ortho_try = MAX( parent_nproc/2, 1 )
+       nproc_ortho_try = MAX( parent_nproc, 1 )
 #else
        nproc_ortho_try = 1
 #endif