diff --git a/pkgs/by-name/sc/scryer-prolog/package.nix b/pkgs/by-name/sc/scryer-prolog/package.nix
index 1fba7059afdd..2c3fe35fa29e 100644
--- a/pkgs/by-name/sc/scryer-prolog/package.nix
+++ b/pkgs/by-name/sc/scryer-prolog/package.nix
@@ -23,7 +23,7 @@ rustPlatform.buildRustPackage (finalAttrs: {
 
   buildInputs = [ openssl ];
 
-  CARGO_FEATURE_USE_SYSTEM_LIBS = true;
+  env.CARGO_FEATURE_USE_SYSTEM_LIBS = true;
 
   meta = {
     description = "Modern Prolog implementation written mostly in Rust";