diff --git a/pkgs/servers/sql/postgresql/topn/default.nix b/pkgs/servers/sql/postgresql/topn/default.nix
new file mode 100644
index 000000000000..6886c80cf50d
--- /dev/null
+++ b/pkgs/servers/sql/postgresql/topn/default.nix
@@ -0,0 +1,32 @@
+{ stdenv, fetchFromGitHub, postgresql, protobufc }:
+
+stdenv.mkDerivation rec {
+  name = "pg_topn-${version}";
+  version = "2.0.2";
+
+  nativeBuildInputs = [ protobufc ];
+  buildInputs = [ postgresql ];
+
+  src = fetchFromGitHub {
+    owner  = "citusdata";
+    repo   = "postgresql-topn";
+    rev    = "refs/tags/v${version}";
+    sha256 = "00hc3hgnqv9xaalizbcvprb7s55sydj2qgk3rhgrdlwg2g025h62";
+  };
+
+  installPhase = ''
+    mkdir -p $out/{lib,share/extension}
+
+    cp *.so      $out/lib
+    cp *.sql     $out/share/extension
+    cp *.control $out/share/extension
+  '';
+
+  meta = with stdenv.lib; {
+    description = "Efficient querying of 'top values' for PostgreSQL";
+    homepage    = https://www.citusdata.com/;
+    maintainers = with maintainers; [ thoughtpolice ];
+    platforms   = platforms.linux;
+    license     = licenses.agpl3;
+  };
+}
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 05f6bf70987f..37f4d6b36562 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -2768,6 +2768,8 @@ with pkgs;
 
   pgtap = callPackage ../servers/sql/postgresql/pgtap {};
 
+  pg_topn = callPackage ../servers/sql/postgresql/topn {};
+
   pigz = callPackage ../tools/compression/pigz { };
 
   pixz = callPackage ../tools/compression/pixz { };