diff --git a/lib/77bit/packjt77.f90 b/lib/77bit/packjt77.f90
index 7204f668b..3cda77d9e 100644
--- a/lib/77bit/packjt77.f90
+++ b/lib/77bit/packjt77.f90
@@ -456,6 +456,7 @@ subroutine unpack77(c77,msg,unpk77_success)
         msg='CQ '//trim(call_2)
      endif
   endif
+  if(msg(1:4).eq.'CQ <') unpk77_success=.false.
 
   return
 end subroutine unpack77