diff --git a/pkgs/development/python-modules/pymaging_png/default.nix b/pkgs/development/python-modules/pymaging_png/default.nix
new file mode 100644
index 00000000000..6756f9deee3
--- /dev/null
+++ b/pkgs/development/python-modules/pymaging_png/default.nix
@@ -0,0 +1,27 @@
+{ stdenv
+, buildPythonPackage
+, fetchFromGitHub
+, pymaging
+}:
+
+buildPythonPackage rec {
+  name = "pymaging-png";
+  version = "unstable-2016-11-16";
+
+  src = fetchFromGitHub {
+    owner = "ojii";
+    repo = "pymaging-png";
+    rev = "83d85c44e4b2342818e6c068065e031a9f81bb9f";
+    sha256 = "1mknxvsq0lr1ffm8amzm3w2prn043c6ghqgpxlkw83r988p5fn57";
+  };
+
+  propagatedBuildInputs = [ pymaging ];
+
+  meta = with stdenv.lib; {
+    description = "Pure Python imaging library with Python 2.6, 2.7, 3.1+ support";
+    homepage    = https://github.com/ojii/pymaging-png/;
+    license     = licenses.mit;
+    maintainers = with maintainers; [ mic92 ];
+  };
+
+}
diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index ca46093a9b6..8d973f7c3dd 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -3465,25 +3465,7 @@ in {
 
   pymaging = callPackage ../development/python-modules/pymaging { };
 
-  pymaging_png = buildPythonPackage rec {
-    name = "pymaging-png-unstable-2016-11-16";
-
-    src = pkgs.fetchFromGitHub {
-      owner = "ojii";
-      repo = "pymaging-png";
-      rev = "83d85c44e4b2342818e6c068065e031a9f81bb9f";
-      sha256 = "1mknxvsq0lr1ffm8amzm3w2prn043c6ghqgpxlkw83r988p5fn57";
-    };
-
-    propagatedBuildInputs = with self; [ pymaging ];
-
-    meta = {
-      description = "Pure Python imaging library with Python 2.6, 2.7, 3.1+ support";
-      homepage    = https://github.com/ojii/pymaging-png/;
-      license     = licenses.mit;
-      maintainers = with maintainers; [ mic92 ];
-    };
-  };
+  pymaging_png = callPackage ../development/python-modules/pymaging_png { };
 
   pyPdf = buildPythonPackage rec {
     name = "pyPdf-1.13";