diff --git a/nixos/modules/tasks/swraid.nix b/nixos/modules/tasks/swraid.nix
index f624294565b0..8985660d80a7 100644
--- a/nixos/modules/tasks/swraid.nix
+++ b/nixos/modules/tasks/swraid.nix
@@ -2,6 +2,8 @@
 
   cfg = config.boot.swraid;
 
+  mdadm_conf = config.environment.etc."mdadm.conf";
+
 in {
   imports = [
     (lib.mkRenamedOptionModule [ "boot" "initrd" "services" "swraid" "enable" ] [ "boot" "swraid" "enable" ])
@@ -36,8 +38,14 @@ in {
   };
 
   config = lib.mkIf cfg.enable {
+    warnings = lib.mkIf
+        ((builtins.match ".*(MAILADDR|PROGRAM).*" mdadm_conf.text) == null)
+        [ "mdadm: Neither MAILADDR nor PROGRAM has been set. This will cause the `mdmon` service to crash." ];
+
     environment.systemPackages = [ pkgs.mdadm ];
 
+    environment.etc."mdadm.conf".text = lib.mkAfter cfg.mdadmConf;
+
     services.udev.packages = [ pkgs.mdadm ];
 
     systemd.packages = [ pkgs.mdadm ];
@@ -59,12 +67,10 @@ in {
         $out/bin/mdadm --version
       '';
 
-      extraFiles."/etc/mdadm.conf".source = pkgs.writeText "mdadm.conf" config.boot.swraid.mdadmConf;
+      extraFiles."/etc/mdadm.conf" = mdadm_conf;
 
       systemd = {
-        contents."/etc/mdadm.conf" = lib.mkIf (cfg.mdadmConf != "") {
-          text = cfg.mdadmConf;
-        };
+        contents."/etc/mdadm.conf".text = mdadm_conf.text;
 
         packages = [ pkgs.mdadm ];
         initrdBin = [ pkgs.mdadm ];
diff --git a/nixos/tests/systemd-initrd-swraid.nix b/nixos/tests/systemd-initrd-swraid.nix
index d87170c92574..cb5b1cb4f535 100644
--- a/nixos/tests/systemd-initrd-swraid.nix
+++ b/nixos/tests/systemd-initrd-swraid.nix
@@ -20,6 +20,9 @@ import ./make-test-python.nix ({ lib, pkgs, ... }: {
         ARRAY /dev/md0 devices=/dev/vdb,/dev/vdc
       '';
     };
+    environment.etc."mdadm.conf".text = ''
+      MAILADDR test@example.com
+    '';
     boot.initrd = {
       systemd = {
         enable = true;
@@ -33,7 +36,7 @@ import ./make-test-python.nix ({ lib, pkgs, ... }: {
 
   testScript = ''
     # Create RAID
-    machine.succeed("mdadm --create --force /dev/md0 -n 2 --level=raid0 /dev/vdb /dev/vdc")
+    machine.succeed("mdadm --create --force /dev/md0 -n 2 --level=raid1 /dev/vdb /dev/vdc --metadata=0.90")
     machine.succeed("mkfs.ext4 -L testraid /dev/md0")
     machine.succeed("mkdir -p /mnt && mount /dev/md0 /mnt && echo hello > /mnt/test && umount /mnt")
 
@@ -48,5 +51,13 @@ import ./make-test-python.nix ({ lib, pkgs, ... }: {
     assert "/dev/md0 on / type ext4" in machine.succeed("mount")
     assert "hello" in machine.succeed("cat /test")
     assert "md0" in machine.succeed("cat /proc/mdstat")
+
+    expected_config = """MAILADDR test@example.com
+
+    ARRAY /dev/md0 devices=/dev/vdb,/dev/vdc
+    """
+    got_config = machine.execute("cat /etc/mdadm.conf")[1]
+    assert expected_config == got_config, repr((expected_config, got_config))
+    machine.wait_for_unit("mdmonitor.service")
   '';
 })