diff --git a/check_timesync.sh b/check_timesync.sh
index 0f162e59..3cbb87ad 100755
--- a/check_timesync.sh
+++ b/check_timesync.sh
@@ -1,12 +1,17 @@
 #!/bin/bash
 #
-# script to check if the system date & time is synced with a ntp server or something else (ie gnss receiver).
+# script to check if the system date & time is synced.
+# It is used to be sure that the logfile name will be correct.
+
+# if you want to use your gnss receiver to set time date and maybe use pps, you need
+# to change this script to use ntpstat instead of timedatectl and modifying the str2str_file.service unit file dependencies
+# to ntp.service or something else.
 
 ntp_exit_code=1
 while [ ${ntp_exit_code} -ne 0 ]
 do
     sleep 1
-    ntpstat > /dev/null
+    timedatectl show | grep 'NTPSynchronized=yes' > /dev/null
     ntp_exit_code=$?
 done
 exit 0
diff --git a/unit/str2str_file.service b/unit/str2str_file.service
index 0837f471..1fac03a0 100644
--- a/unit/str2str_file.service
+++ b/unit/str2str_file.service
@@ -1,6 +1,6 @@
 [Unit]
 Description=RTKBase File - Log data
-Requires=str2str_tcp.service ntp.service
+Requires=str2str_tcp.service systemd-timesyncd.service
 
 [Service]
 Type=forking