diff --git a/drivers/syslog/syslog_stream.c b/drivers/syslog/syslog_stream.c
index 2119b9e917..a14a5d4f12 100644
--- a/drivers/syslog/syslog_stream.c
+++ b/drivers/syslog/syslog_stream.c
@@ -98,6 +98,7 @@ static int syslogstream_flush(FAR struct lib_syslogstream_s *stream)
  * Name: syslogstream_addchar
  ****************************************************************************/
 
+#ifdef CONFIG_SYSLOG_BUFFER
 static void syslogstream_addchar(FAR struct lib_syslogstream_s *stream, int ch)
 {
   FAR struct iob_s *iob = stream->iob;
@@ -120,6 +121,7 @@ static void syslogstream_addchar(FAR struct lib_syslogstream_s *stream, int ch)
       syslogstream_flush(stream);
     }
 }
+#endif
 
 /****************************************************************************
  * Name: syslogstream_putc