diff --git a/maintainers/scripts/haskell/regenerate-hackage-packages.sh b/maintainers/scripts/haskell/regenerate-hackage-packages.sh
index 2f8d7ec3cbcf..e7652540ab8b 100755
--- a/maintainers/scripts/haskell/regenerate-hackage-packages.sh
+++ b/maintainers/scripts/haskell/regenerate-hackage-packages.sh
@@ -89,7 +89,6 @@ compiler_config="$(nix-build -A haskellPackages.cabal2nix-unstable.compilerConfi
 
 echo "Running hackage2nix to regenerate pkgs/development/haskell-modules/hackage-packages.nix …"
 run_hackage2nix
-nixfmt pkgs/development/haskell-modules/hackage-packages.nix
 
 if [[ "$REGENERATE_TRANSITIVE" -eq 1 ]]; then
 
@@ -103,6 +102,7 @@ run_hackage2nix
 
 fi
 
+nixfmt pkgs/development/haskell-modules/hackage-packages.nix
 
 if [[ "$DO_COMMIT" -eq 1 ]]; then
 git add pkgs/development/haskell-modules/configuration-hackage2nix/transitive-broken.yaml
diff --git a/pkgs/development/haskell-modules/cabal2nix-unstable.nix b/pkgs/development/haskell-modules/cabal2nix-unstable.nix
index 538f9795cab3..3c8c37039743 100644
--- a/pkgs/development/haskell-modules/cabal2nix-unstable.nix
+++ b/pkgs/development/haskell-modules/cabal2nix-unstable.nix
@@ -2,6 +2,7 @@
 {
   mkDerivation,
   aeson,
+  ansi-terminal,
   ansi-wl-pprint,
   base,
   bytestring,
@@ -34,16 +35,17 @@
 }:
 mkDerivation {
   pname = "cabal2nix";
-  version = "unstable-2025-03-03";
+  version = "unstable-2025-04-01";
   src = fetchzip {
-    url = "https://github.com/NixOS/cabal2nix/archive/001aa9757c178c7d3069bc828cfea41b550c26ef.tar.gz";
-    sha256 = "1f5kxhbr78h4d0i4lhfkqijc783jlrpfrv7gq2x37c94p213agg4";
+    url = "https://github.com/NixOS/cabal2nix/archive/9dacfdb1ddb22f8e24c984541724784016d5231b.tar.gz";
+    sha256 = "1hyfmkhicy2ha9ax0vb4ml11f6z7k9mqydm5s1g06b1z64jf4y7r";
   };
   postUnpack = "sourceRoot+=/cabal2nix; echo source root reset to $sourceRoot";
   isLibrary = true;
   isExecutable = true;
   libraryHaskellDepends = [
     aeson
+    ansi-terminal
     ansi-wl-pprint
     base
     bytestring
diff --git a/pkgs/development/haskell-modules/configuration-hackage2nix/transitive-broken.yaml b/pkgs/development/haskell-modules/configuration-hackage2nix/transitive-broken.yaml
index 43edcf60d6f4..35ed7cc9536d 100644
--- a/pkgs/development/haskell-modules/configuration-hackage2nix/transitive-broken.yaml
+++ b/pkgs/development/haskell-modules/configuration-hackage2nix/transitive-broken.yaml
@@ -1578,7 +1578,6 @@ dont-distribute-packages:
  - haskell-docs
  - haskell-eigen-util
  - haskell-ftp
- - haskell-language-server
  - haskell-lsp
  - haskell-lsp-client
  - haskell-pdf-presenter
diff --git a/pkgs/development/haskell-modules/configuration-nix.nix b/pkgs/development/haskell-modules/configuration-nix.nix
index 15565a3f4398..13a384cc0886 100644
--- a/pkgs/development/haskell-modules/configuration-nix.nix
+++ b/pkgs/development/haskell-modules/configuration-nix.nix
@@ -1654,16 +1654,7 @@ builtins.intersectAttrs super {
     librarySystemDepends = (drv.librarySystemDepends or [ ]) ++ [ pkgs.libpq ];
   }) super.postgresql-libpq-configure;
 
-  postgresql-libpq-pkgconfig =
-    addPkgconfigDepend
-      # Building postgresql-libpq with PG17 in pkgsStatic works fine, but downstream can't link against it with:
-      # > /nix/store/7ir63m9sbqzflf3yfynn45i109w6a5iz-x86_64-unknown-linux-musl-binutils-2.43.1/bin/x86_64-unknown-linux-musl-ld:
-      #   /nix/store/vj7fwxbyvs15zrjbb9vafxbwmc05hl70-postgresql-static-x86_64-unknown-linux-musl-17.2-dev/lib/libpq.a(fe-connect.o):
-      #   in function `PQsetClientEncoding':
-      # > (.text.PQsetClientEncoding+0xdf): undefined reference to `pg_encoding_to_char'
-      # Falling back to v16 to work around it.
-      (if pkgs.stdenv.hostPlatform.isStatic then pkgs.postgresql_16 else pkgs.libpq)
-      super.postgresql-libpq-pkgconfig;
+  postgresql-libpq-pkgconfig = addPkgconfigDepend pkgs.libpq super.postgresql-libpq-pkgconfig;
 
   # Test failure is related to a GHC implementation detail of primitives and doesn't
   # cause actual problems in dependent packages, see https://github.com/lehins/pvar/issues/4
diff --git a/pkgs/development/haskell-modules/hackage-packages.nix b/pkgs/development/haskell-modules/hackage-packages.nix
index cf386b296546..857464ae4abd 100644
--- a/pkgs/development/haskell-modules/hackage-packages.nix
+++ b/pkgs/development/haskell-modules/hackage-packages.nix
@@ -17783,10 +17783,10 @@ self: {
       Cabal,
       convertible,
       HDBC,
+      libpq,
       mtl,
       old-time,
       parsec,
-      postgresql,
       time,
       utf8-string,
     }:
@@ -17811,11 +17811,11 @@ self: {
         time
         utf8-string
       ];
-      librarySystemDepends = [ postgresql ];
+      librarySystemDepends = [ libpq ];
       description = "PostgreSQL driver for HDBC";
       license = lib.licenses.bsd3;
     }
-  ) { inherit (pkgs) postgresql; };
+  ) { inherit (pkgs) libpq; };
 
   "HDBC-postgresql-hstore" = callPackage (
     {
@@ -304443,7 +304443,6 @@ self: {
       doHaddock = false;
       description = "LSP server for GHC";
       license = lib.licenses.asl20;
-      hydraPlatforms = lib.platforms.none;
       maintainers = [ lib.maintainers.maralorn ];
     }
   ) { };
@@ -307786,8 +307785,8 @@ self: {
       haskelldb-hdbc,
       HDBC,
       HDBC-postgresql,
+      libpq,
       mtl,
-      postgresql,
     }:
     mkDerivation {
       pname = "haskelldb-hdbc-postgresql";
@@ -307803,13 +307802,13 @@ self: {
         HDBC-postgresql
         mtl
       ];
-      executableSystemDepends = [ postgresql ];
+      executableSystemDepends = [ libpq ];
       description = "HaskellDB support for the HDBC PostgreSQL driver";
       license = lib.licenses.bsd3;
       hydraPlatforms = lib.platforms.none;
       mainProgram = "DBDirect-hdbc-postgresql";
     }
-  ) { inherit (pkgs) postgresql; };
+  ) { inherit (pkgs) libpq; };
 
   "haskelldb-hdbc-sqlite3" = callPackage (
     {
@@ -357353,8 +357352,8 @@ self: {
       mkDerivation,
       base,
       hsql,
+      libpq,
       old-time,
-      postgresql,
     }:
     mkDerivation {
       pname = "hsql-postgresql";
@@ -357365,12 +357364,12 @@ self: {
         hsql
         old-time
       ];
-      librarySystemDepends = [ postgresql ];
+      librarySystemDepends = [ libpq ];
       description = "A Haskell Interface to PostgreSQL via the PQ library";
       license = lib.licenses.bsd3;
       hydraPlatforms = lib.platforms.none;
     }
-  ) { inherit (pkgs) postgresql; };
+  ) { inherit (pkgs) libpq; };
 
   "hsql-sqlite3" = callPackage (
     {
@@ -417918,7 +417917,7 @@ self: {
       mkDerivation,
       base,
       bytestring,
-      postgresql,
+      libpq,
       unix,
     }:
     mkDerivation {
@@ -417930,13 +417929,13 @@ self: {
         bytestring
         unix
       ];
-      librarySystemDepends = [ postgresql ];
+      librarySystemDepends = [ libpq ];
       description = "libpq binding for Haskell";
       license = lib.licenses.bsd3;
       hydraPlatforms = lib.platforms.none;
       broken = true;
     }
-  ) { inherit (pkgs) postgresql; };
+  ) { inherit (pkgs) libpq; };
 
   "libraft" = callPackage (
     {