1 files changed, 1 insertions, 1 deletions

diff --git a/src/process.c b/src/process.c
index 2c3ad252a68..d056e1111bf 100644
--- a/src/process.c
+++ b/src/process.c
@@ -1841,7 +1841,7 @@ wait_reading_process_input (time_limit, microsecs, read_kbd, do_display)
           else
             error("select error: %s", sys_errlist[xerrno]);
         }
-#ifdef sun
+#if defined(sun) && !defined(USG5_4)
       else if (nfds > 0 && FD_ISSET (0, &Available) && interrupt_input)
         /* System sometimes fails to deliver SIGIO.  */
         kill (getpid (), SIGIO);