diff --git a/cabal.project b/cabal.project
index d6e389a8d80..725cbd32fef 100644
--- a/cabal.project
+++ b/cabal.project
@@ -174,7 +174,6 @@ source-repository-package
     typed-protocols
     typed-protocols-examples
     Win32-network
-    ouroboros-network-testing
 
 -- Needed for the Windows cabal constraint solver.
 max-backjumps: 10000
diff --git a/nix/sources.json b/nix/sources.json
index ccfa3644107..742d43f482c 100644
--- a/nix/sources.json
+++ b/nix/sources.json
@@ -29,10 +29,10 @@
         "homepage": "https://input-output-hk.github.io/haskell.nix",
         "owner": "input-output-hk",
         "repo": "haskell.nix",
-        "rev": "7e49dd7f126210d8bfbde2dda93cf6d72d7b3e2e",
-        "sha256": "076jk9x5y1g37bn2afxrcijf1xf1yinljh8dbzv553i43l989k5n",
+        "rev": "505130bfdaa9ecff5f50c4c415d4cb7db7089716",
+        "sha256": "1j193vhc7gd22lsk6dd8lfkq64aj7xmas23sb3gkr1v6ihchpaj6",
         "type": "tarball",
-        "url": "https://github.com/input-output-hk/haskell.nix/archive/7e49dd7f126210d8bfbde2dda93cf6d72d7b3e2e.tar.gz",
+        "url": "https://github.com/input-output-hk/haskell.nix/archive/505130bfdaa9ecff5f50c4c415d4cb7db7089716.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
     "iohk-nix": {