diff --git a/nixos/tests/telegraf.nix b/nixos/tests/telegraf.nix
index 938bbd518b5a..7f4b36752582 100644
--- a/nixos/tests/telegraf.nix
+++ b/nixos/tests/telegraf.nix
@@ -6,9 +6,9 @@ import ./make-test-python.nix ({ pkgs, ...} : {
 
   machine = { ... }: {
     services.telegraf.enable = true;
-    services.telegraf.environmentFiles = [pkgs.writeText "secrets" ''
+    services.telegraf.environmentFiles = [(pkgs.writeText "secrets" ''
       SECRET=example
-    ''];
+    '')];
     services.telegraf.extraConfig = {
       agent.interval = "1s";
       agent.flush_interval = "1s";