diff --git a/pkgs/servers/sql/postgresql/pg_similarity/default.nix b/pkgs/servers/sql/postgresql/pg_similarity/default.nix
new file mode 100644
index 000000000000..32945c9fa62b
--- /dev/null
+++ b/pkgs/servers/sql/postgresql/pg_similarity/default.nix
@@ -0,0 +1,31 @@
+{ stdenv, lib, fetchFromGitHub, gcc, postgresql }:
+
+stdenv.mkDerivation {
+
+  name = "pg_similarity-1.0";
+  src = fetchFromGitHub {
+    owner = "eulerto";
+    repo = "pg_similarity";
+    rev = "be1a8b08c8716e59b89982557da9ea68cdf868c5";
+    sha256 = "1z4v4r2yccdr8kz3935fnk1bc5vj0qj0apscldyap4wxlyi89xim";
+  };
+
+  buildInputs = [ postgresql gcc ];
+  buildPhase = "USE_PGXS=1 make";
+  installPhase = ''
+    mkdir -p $out/bin   # for buildEnv to setup proper symlinks
+    install -D pg_similarity.so -t $out/lib/
+    install -D ./{pg_similarity--unpackaged--1.0.sql,pg_similarity--1.0.sql,pg_similarity.control} -t $out/share/extension
+  '';
+
+  meta = {
+    description = ''
+       pg_similarity is an extension to support similarity queries on PostgreSQL. The implementation
+       is tightly integrated in the RDBMS in the sense that it defines operators so instead of the traditional
+       operators (= and <>) you can use ~~~ and ~!~ (any of these operators represents a similarity function).
+    '';
+    platforms = stdenv.lib.platforms.linux;
+    license = stdenv.lib.licenses.gpl2;
+    maintainers = with lib.maintainers; [ danbst ];
+  };
+}
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index ab4c2946d139..a63fe3d2e1eb 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -8926,6 +8926,8 @@ in
 
   pg_repack = callPackage ../servers/sql/postgresql/pg_repack {};
 
+  pg_similarity = callPackage ../servers/sql/postgresql/pg_similarity {};
+
   phonon = callPackage ../development/libraries/phonon {};
 
   phonon-backend-gstreamer = callPackage ../development/libraries/phonon/backends/gstreamer.nix {};