diff --git a/pkgs/applications/networking/browsers/castor/default.nix b/pkgs/applications/networking/browsers/castor/default.nix
index dd8ddd2dccb..c9ad213cf1d 100644
--- a/pkgs/applications/networking/browsers/castor/default.nix
+++ b/pkgs/applications/networking/browsers/castor/default.nix
@@ -39,8 +39,7 @@ rustPlatform.buildRustPackage rec {
   postInstall = "make PREFIX=$out copy-data";
 
   # Sometimes tests fail when run in parallel
-  #checkFlags = [ "--test-threads=1" ];
-  doCheck = false;
+  cargoParallelTestThreads = false;
 
   meta = with stdenv.lib; {
     description = "A graphical client for plain-text protocols written in Rust with GTK. It currently supports the Gemini, Gopher and Finger protocols";
@@ -49,4 +48,3 @@ rustPlatform.buildRustPackage rec {
     maintainers = with maintainers; [ fgaz ];
   };
 }
-