diff --git a/nixos/modules/services/networking/chrony.nix b/nixos/modules/services/networking/chrony.nix
index a363b545d649..9b8005e706ae 100644
--- a/nixos/modules/services/networking/chrony.nix
+++ b/nixos/modules/services/networking/chrony.nix
@@ -93,6 +93,8 @@ in
 
     services.timesyncd.enable = mkForce false;
 
+    systemd.services.systemd-timedated.environment = { SYSTEMD_TIMEDATED_NTP_SERVICES = "chronyd.service"; };
+
     systemd.services.chronyd =
       { description = "chrony NTP daemon";
 
diff --git a/nixos/modules/services/networking/ntpd.nix b/nixos/modules/services/networking/ntpd.nix
index 342350d49ab3..32174100b0f7 100644
--- a/nixos/modules/services/networking/ntpd.nix
+++ b/nixos/modules/services/networking/ntpd.nix
@@ -67,6 +67,8 @@ in
     environment.systemPackages = [ pkgs.ntp ];
     services.timesyncd.enable = mkForce false;
 
+    systemd.services.systemd-timedated.environment = { SYSTEMD_TIMEDATED_NTP_SERVICES = "ntpd.service"; };
+
     users.users = singleton
       { name = ntpUser;
         uid = config.ids.uids.ntp;