diff --git a/pkgs/servers/sql/postgresql/ext/pg_auto_failover.nix b/pkgs/servers/sql/postgresql/ext/pg_auto_failover.nix
index ed0bfde0caba..42d055a029ae 100644
--- a/pkgs/servers/sql/postgresql/ext/pg_auto_failover.nix
+++ b/pkgs/servers/sql/postgresql/ext/pg_auto_failover.nix
@@ -1,4 +1,4 @@
-{ lib, stdenv, fetchFromGitHub, postgresql, openssl, zlib, readline, libkrb5, libxcrypt }:
+{ lib, stdenv, fetchFromGitHub, postgresql }:
 
 stdenv.mkDerivation rec {
   pname = "pg_auto_failover";
diff --git a/pkgs/servers/sql/postgresql/ext/pg_repack.nix b/pkgs/servers/sql/postgresql/ext/pg_repack.nix
index b2a608a2bc39..3361e2100da2 100644
--- a/pkgs/servers/sql/postgresql/ext/pg_repack.nix
+++ b/pkgs/servers/sql/postgresql/ext/pg_repack.nix
@@ -4,7 +4,6 @@
 , postgresql
 , postgresqlTestHook
 , testers
-, zlib
 }:
 
 stdenv.mkDerivation (finalAttrs: {
diff --git a/pkgs/servers/sql/postgresql/ext/pg_similarity.nix b/pkgs/servers/sql/postgresql/ext/pg_similarity.nix
index 20e5299da25a..a0669331055b 100644
--- a/pkgs/servers/sql/postgresql/ext/pg_similarity.nix
+++ b/pkgs/servers/sql/postgresql/ext/pg_similarity.nix
@@ -12,7 +12,9 @@ stdenv.mkDerivation {
   };
 
   buildInputs = [ postgresql gcc ];
-  buildPhase = "USE_PGXS=1 make";
+
+  makeFlags = [ "USE_PGXS=1" ];
+
   installPhase = ''
     install -D pg_similarity${postgresql.dlSuffix} -t $out/lib/
     install -D ./{pg_similarity--unpackaged--1.0.sql,pg_similarity--1.0.sql,pg_similarity.control} -t $out/share/postgresql/extension
diff --git a/pkgs/servers/sql/postgresql/ext/plr.nix b/pkgs/servers/sql/postgresql/ext/plr.nix
index 1800b424716f..05d22c19a8b0 100644
--- a/pkgs/servers/sql/postgresql/ext/plr.nix
+++ b/pkgs/servers/sql/postgresql/ext/plr.nix
@@ -13,9 +13,9 @@ stdenv.mkDerivation rec {
 
   nativeBuildInputs = [ pkg-config ];
   buildInputs = [ R postgresql ];
-  preBuild = ''
-    export USE_PGXS=1
-  '';
+
+  makeFlags = [ "USE_PGXS=1" ];
+
   installPhase = ''
     install -D plr${postgresql.dlSuffix} -t $out/lib/
     install -D {plr--*.sql,plr.control} -t $out/share/postgresql/extension
diff --git a/pkgs/servers/sql/postgresql/ext/repmgr.nix b/pkgs/servers/sql/postgresql/ext/repmgr.nix
index dd55743a43cf..565f3fdaf60d 100644
--- a/pkgs/servers/sql/postgresql/ext/repmgr.nix
+++ b/pkgs/servers/sql/postgresql/ext/repmgr.nix
@@ -5,7 +5,6 @@
 , flex
 , curl
 , json_c
-, libxcrypt
 }:
 
 stdenv.mkDerivation rec {
diff --git a/pkgs/servers/sql/postgresql/ext/system_stats.nix b/pkgs/servers/sql/postgresql/ext/system_stats.nix
index bc2a0973b95f..c1700fc0380d 100644
--- a/pkgs/servers/sql/postgresql/ext/system_stats.nix
+++ b/pkgs/servers/sql/postgresql/ext/system_stats.nix
@@ -6,7 +6,7 @@
 }:
 stdenv.mkDerivation rec {
   pname = "system_stats";
-  version = "3.0";
+  version = "3.2";
 
   buildInputs = [ postgresql ];
 
@@ -14,7 +14,7 @@ stdenv.mkDerivation rec {
     owner = "EnterpriseDB";
     repo = "system_stats";
     rev = "v${version}";
-    hash = "sha256-LuX7/LOi0rl6L/kjbjq7rr2zPcGIOYB7hdZBNJ9xqak=";
+    hash = "sha256-/xXnui0S0ZjRw7P8kMAgttHVv8T41aOhM3pM8P0OTig=";
   };
 
   installPhase = ''