diff --git a/cabal.project b/cabal.project
index f838bc6267c..a699906fa98 100644
--- a/cabal.project
+++ b/cabal.project
@@ -24,9 +24,9 @@ source-repository-package
   -- !WARNING!:
   -- MAKE SURE THIS POINTS TO A COMMIT IN `MAlonzo-code` BEFORE MERGE!
   subdir: generated
+  --sha256: sha256-by921yC1MaZI58kyrtEGGKqmt9jMnVsPLfQtP4raJPw=
   tag: be51adff014214c15fed718d396bb8a6d955f9e1
 
---sha256: sha256-by921yC1MaZI58kyrtEGGKqmt9jMnVsPLfQtP4raJPw=
 -- NOTE: If you would like to update the above, look for the `MAlonzo-code`
 -- branch in the `formal-ledger-specifications` repo and copy the SHA of
 -- the commit you need. The `MAlonzo-code` branch functions like an alternative
diff --git a/flake.nix b/flake.nix
index 31da7fb4e46..7519fde55fa 100644
--- a/flake.nix
+++ b/flake.nix
@@ -80,6 +80,8 @@
           '';
 
           shell = {
+            # Due to plutus-tx-plugin being a bit special, we need to augment the default package selection.
+            packages = ps: builtins.attrValues (nixpkgs.haskell-nix.haskellLib.selectLocalPackages ps) ++ [ps.plutus-tx-plugin];
 
             # force LANG to be UTF-8, otherwise GHC might choke on UTF encoded data.
             shellHook = ''