diff --git a/src/process.c b/src/process.c
index 6ba27a33f4..5763101cbf 100644
--- a/src/process.c
+++ b/src/process.c
@@ -5458,6 +5458,9 @@ wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd,
       /*  If we woke up due to SIGWINCH, actually change size now.  */
       do_pending_window_change (0);
 
+      if (wait_proc->nbytes_read != prev_wait_proc_nbytes_read)
+        break;
+
       if (nfds == 0)
 	{
           /* Exit the main loop if we've passed the requested timeout,