diff --git a/pkgs/development/haskell-modules/generic-builder.nix b/pkgs/development/haskell-modules/generic-builder.nix
index 43676f1e72e..7a421e4f7b6 100644
--- a/pkgs/development/haskell-modules/generic-builder.nix
+++ b/pkgs/development/haskell-modules/generic-builder.nix
@@ -151,7 +151,7 @@ let
   ghcCommand' = if isGhcjs then "ghcjs" else "ghc";
   crossPrefix = if (ghc.cross or null) != null then "${ghc.cross.config}-" else "";
   ghcCommand = "${crossPrefix}${ghcCommand'}";
-  ghcCommandCaps= lib.toUpper ghcCommand';
+  ghcCommandCaps= toUpper ghcCommand';
 
 in