diff --git a/nixos/modules/services/monitoring/prometheus/default.nix b/nixos/modules/services/monitoring/prometheus/default.nix
index 8fe689ef3dbba..e6ff2bfe1fa87 100644
--- a/nixos/modules/services/monitoring/prometheus/default.nix
+++ b/nixos/modules/services/monitoring/prometheus/default.nix
@@ -47,7 +47,7 @@ let
 
   cmdlineArgs = cfg.extraFlags ++ [
     "--storage.tsdb.path=${workingDir}/data/"
-    "--config.file=/run/prometheus/prometheus-substituted.yaml"
+    "--config.file=${prometheusYml}"
     "--web.listen-address=${cfg.listenAddress}:${builtins.toString cfg.port}"
     "--alertmanager.notification-queue-capacity=${toString cfg.alertmanagerNotificationQueueCapacity}"
     "--alertmanager.timeout=${toString cfg.alertmanagerTimeout}s"
@@ -733,45 +733,6 @@ in {
       '';
     };
 
-    environmentFile = mkOption {
-      type = types.nullOr types.path;
-      default = null;
-      example = "/root/prometheus.env";
-      description = ''
-        Environment file as defined in <citerefentry>
-        <refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum>
-        </citerefentry>.
-
-        Secrets may be passed to the service without adding them to the
-        world-readable Nix store, by specifying placeholder variables as
-        the option value in Nix and setting these variables accordingly in the
-        environment file.
-
-        Environment variables from this file will be interpolated into the
-        config file using envsubst with this syntax:
-        <literal>$ENVIRONMENT ''${VARIABLE}</literal>
-
-        <programlisting>
-          # Example scrape config entry handling an OAuth bearer token
-          {
-            job_name = "home_assistant";
-            metrics_path = "/api/prometheus";
-            scheme = "https";
-            bearer_token = "\''${HOME_ASSISTANT_BEARER_TOKEN}";
-            [...]
-          }
-        </programlisting>
-
-        <programlisting>
-          # Content of the environment file
-          HOME_ASSISTANT_BEARER_TOKEN=someoauthbearertoken
-        </programlisting>
-
-        Note that this file needs to be available on the host on which
-        <literal>Prometheus</literal> is running.
-      '';
-    };
-
     configText = mkOption {
       type = types.nullOr types.lines;
       default = null;
@@ -930,19 +891,12 @@ in {
     systemd.services.prometheus = {
       wantedBy = [ "multi-user.target" ];
       after    = [ "network.target" ];
-      preStart = ''
-         ${lib.getBin pkgs.envsubst}/bin/envsubst -o "/run/prometheus/prometheus-substituted.yaml" \
-                                                  -i "${prometheusYml}"
-      '';
       serviceConfig = {
         ExecStart = "${cfg.package}/bin/prometheus" +
           optionalString (length cmdlineArgs != 0) (" \\\n  " +
             concatStringsSep " \\\n  " cmdlineArgs);
         User = "prometheus";
         Restart  = "always";
-        EnvironmentFile = mkIf (cfg.environmentFile != null) [ cfg.environmentFile ];
-        RuntimeDirectory = "prometheus";
-        RuntimeDirectoryMode = "0700";
         WorkingDirectory = workingDir;
         StateDirectory = cfg.stateDir;
         StateDirectoryMode = "0700";