diff --git a/flake.nix b/flake.nix
index cf11745cac34b20c94bcf9f18f75b3278074167e..153768b55982c4d870e328e9a17415bdc6a99eb5 100644
--- a/flake.nix
+++ b/flake.nix
@@ -84,7 +84,7 @@
               export PKG_CONFIG_PATH=${pkgs.lib.makeSearchPath "lib/pkgconfig" [pkgs.zlib.dev]}
 
               find .
-              # ghc-pkg check --package-db .cabal/store/ghc-8.10.7/package.db
+              ghc-pkg check --package-db .cabal/store/ghc-8.10.7/package.db
               cabal update hackage.haskell.org
               cabal run tests
             '';