diff --git a/drivers/syslog/syslog_filechannel.c b/drivers/syslog/syslog_filechannel.c
index a5cd35fbe5..b3a7a42c22 100644
--- a/drivers/syslog/syslog_filechannel.c
+++ b/drivers/syslog/syslog_filechannel.c
@@ -58,7 +58,7 @@ static void log_separate(FAR const char *log_file)
 {
   struct file fp;
 
-  if (file_open(&fp, log_file, O_WRONLY) < 0)
+  if (file_open(&fp, log_file, (O_WRONLY | O_APPEND)) < 0)
     {
       return;
     }