diff --git a/overlay_interface.c b/overlay_interface.c
index 6efafea4..9a241a11 100644
--- a/overlay_interface.c
+++ b/overlay_interface.c
@@ -751,10 +751,14 @@ overlay_broadcast_ensemble(overlay_interface *interface,
        only purpose is to find out the offset to print in the DEBUG statement.  It is vulnerable
        to a race condition with other processes appending to the same file. */
       off_t fsize = lseek(interface->alarm.poll.fd, (off_t) 0, SEEK_END);
-      if (fsize == -1)
-	return WHY_perror("lseek");
-      if (config.debug.overlayinterfaces)
-	DEBUGF("Write to interface %s at offset=%d", interface->name, fsize);
+      /* Don't complain if the seek fails because we are writing to a pipe or device that does
+	 not support seeking. */
+      if (errno!=ESPIPE) {
+	if (fsize == -1)
+	  return WHY_perror("lseek");
+	if (config.debug.overlayinterfaces)
+	  DEBUGF("Write to interface %s at offset=%d", interface->name, fsize);
+      }
       ssize_t nwrite = write(interface->alarm.poll.fd, &packet, sizeof(packet));
       if (nwrite == -1)
 	return WHY_perror("write");