diff --git a/overlays/10-previews.nix b/overlays/10-previews.nix
index d878f492..58464b10 100644
--- a/overlays/10-previews.nix
+++ b/overlays/10-previews.nix
@@ -3,6 +3,5 @@ let
   unstable = import super.sources.nixos-unstable { };
 in
 {
-  inherit (unstable) laminar upterm syncthing vimPlugins dhallPackages fzf gomuks neochat mirage-im nheko;
-  matrix-synapse-tools.rust-synapse-compress-state = unstable.matrix-synapse-tools.rust-synapse-compress-state;
+  inherit (unstable) laminar upterm syncthing vimPlugins dhallPackages fzf gomuks neochat mirage-im nheko haskellPackages ghc cachix nix-output-monitor matrix-synapse-tools;
 }
diff --git a/overlays/30-ghc.nix b/overlays/30-ghc.nix
index e80f4a0b..6df4d8eb 100644
--- a/overlays/30-ghc.nix
+++ b/overlays/30-ghc.nix
@@ -1,8 +1,7 @@
-self: super:
+final: prev:
 let
-  inherit (super) fetchFromGitHub;
-  unstable = import super.sources.nixos-unstable { };
-  inherit (unstable.haskell.lib) overrideCabal unmarkBroken doJailbreak dontCheck;
+  inherit (prev) ghc haskellPackages;
+  inherit (prev.haskell.lib) overrideCabal unmarkBroken doJailbreak dontCheck;
   makeHaskellScriptPackages = p: {
     inherit (p)
       aeson shh string-interpolate relude replace-megaparsec async say
@@ -20,16 +19,8 @@ let
         hedgehog nix-derivation req
         ;
     } // makeHaskellScriptPackages p;
-  overrides = self: super: {
-    generic-optics = dontCheck (unmarkBroken super.generic-optics);
-  };
-  haskellPackages = unstable.haskellPackages.extend overrides;
-  ghc = haskellPackages.ghc;
 in
 {
-  inherit ghc haskellPackages;
-  cachix = unstable.cachix;
-  nix-output-monitor = unstable.nix-output-monitor;
   myHaskellPackages = makeHaskellPackages haskellPackages;
   myHaskellScriptPackages = makeHaskellScriptPackages haskellPackages;
   ghcWithPackages = ghc.withHoogle (p: builtins.attrValues (makeHaskellPackages p));
diff --git a/overlays/logfeed/default.nix b/overlays/logfeed/default.nix
index c9d15c75..e39b728a 100644
--- a/overlays/logfeed/default.nix
+++ b/overlays/logfeed/default.nix
@@ -1,7 +1,4 @@
 final: prev:
-let
-  master = import prev.sources.nixpkgs-master { };
-in
 {
-  logfeed = master.haskellPackages.callCabal2nix "logfeed" prev.sources.logfeed { };
+  logfeed = prev.haskellPackages.callCabal2nix "logfeed" prev.sources.logfeed { };
 }