diff --git a/lib/fst4/fst4sim.f90 b/lib/fst4/fst4sim.f90
index 28caf2fe0..453c1fe97 100644
--- a/lib/fst4/fst4sim.f90
+++ b/lib/fst4/fst4sim.f90
@@ -93,6 +93,10 @@ program fst4sim
    if(i3.eq.1) then
       write(*,*) '         mycall                         hiscall                    hisgrid'
       write(*,'(28i1,1x,i1,1x,28i1,1x,i1,1x,i1,1x,15i1,1x,3i1)') msgbits(1:77)
+   elseif(i3.eq.0 .and. n3.eq.6) then
+      write(*,*) '50-bit message'
+      write(*,'(a50)') '01234567890123456789012345678901234567890123456789'
+      write(*,'(50i1,1x,24i1)') msgbits(1:50),msgbits(51:74)
    else
       write(*,'(a14)') 'Message bits: '
       write(*,'(77i1,1x,24i1)') msgbits