diff --git a/nixos/modules/config/malloc.nix b/nixos/modules/config/malloc.nix
index bc6a27673e3e..ebc173a642e8 100644
--- a/nixos/modules/config/malloc.nix
+++ b/nixos/modules/config/malloc.nix
@@ -142,10 +142,14 @@ in
         # so we can warn the user about the change.
         legacyOptionsUsed = lib.lists.filter (opt: lib.strings.hasInfix opt scudoOpts) legacyOptionNames;
       in
-      lib.optional (cfg.provider == "scudo" && legacyOptionsUsed != [ ]) ''
-        environment.variables.SCUDO_OPTIONS: ${lib.concatStringsSep ", " legacyOptionsUsed} is/are no longer valid Scudo options.
-        Use snake_case instead of CamelCase: https://llvm.org/docs/ScudoHardenedAllocator.html#options
-      '';
+      lib.optional
+        (
+          config.environment.variables ? SCUDO_OPTIONS && cfg.provider == "scudo" && legacyOptionsUsed != [ ]
+        )
+        ''
+          environment.variables.SCUDO_OPTIONS: ${lib.concatStringsSep ", " legacyOptionsUsed} is/are no longer valid Scudo options.
+          Use snake_case instead of CamelCase: https://llvm.org/docs/ScudoHardenedAllocator.html#options
+        '';
 
     environment.etc."ld-nix.so.preload".text = ''
       ${providerLibPath}