diff --git a/lib/util.nix b/lib/util.nix
index aeca2af..deeda06 100644
--- a/lib/util.nix
+++ b/lib/util.nix
@@ -1,4 +1,4 @@
-with builtins; let
+{ lib, ... }: with builtins; let
   collectAttrFragments = successPredicate: stopPredicate: attrs: let
     _collectAttrFragments = attrs:
       concatMap (key: _collectAttrFragmentsBelowKey key attrs.${key}) (attrNames attrs)
@@ -24,7 +24,7 @@ with builtins; let
 
   toEnvValue = value:
     if isBool value then (if value then "true" else "false")
-    else if isList value then "[${concatStringSep ";" value}]"
+    else if isList value then "[${lib.strings.concatStringsSep ";" value}]"
     else value
   ;
 
diff --git a/modules/pihole-container.factory.nix b/modules/pihole-container.factory.nix
index 6c54b9b..3c2ff59 100644
--- a/modules/pihole-container.factory.nix
+++ b/modules/pihole-container.factory.nix
@@ -1,5 +1,5 @@
 { piholeFlake, lingerFlake }: { config, pkgs, lib, ... }: with lib; with builtins; let
-  inherit (import ../lib/util.nix) extractContainerEnvVars extractContainerFTLEnvVars;
+  inherit ((import ../lib/util.nix) { inherit lib; }) extractContainerEnvVars extractContainerFTLEnvVars;
 
   mkContainerEnvOption = { envVar, ... }@optionAttrs:
     (mkOption (removeAttrs optionAttrs [ "envVar" ]))