diff --git a/nixos/modules/services/networking/cloudflare-ddns.nix b/nixos/modules/services/networking/cloudflare-ddns.nix
index 183ead4a0f0c..35e37f1ae504 100644
--- a/nixos/modules/services/networking/cloudflare-ddns.nix
+++ b/nixos/modules/services/networking/cloudflare-ddns.nix
@@ -7,7 +7,6 @@
 let
   cfg = config.services.cloudflare-ddns;
 
-  boolToString = b: if b then "true" else "false";
   formatList = l: lib.concatStringsSep "," l;
 in
 {
@@ -265,7 +264,7 @@ in
           let
             toEnv = name: value: "${name}=\"${toString value}\"";
             toEnvList = name: value: "${name}=\"${formatList value}\"";
-            toEnvBool = name: value: "${name}=\"${boolToString value}\"";
+            toEnvBool = name: value: "${name}=\"${lib.boolToString value}\"";
             toEnvMaybe =
               pred: name: value:
               lib.optionalString pred (toEnv name value);