diff --git a/pkgs/development/interpreters/python/cpython/2.6/default.nix b/pkgs/development/interpreters/python/cpython/2.6/default.nix
index 64f2b80d09fa..9a4c2d5b3981 100644
--- a/pkgs/development/interpreters/python/cpython/2.6/default.nix
+++ b/pkgs/development/interpreters/python/cpython/2.6/default.nix
@@ -1,6 +1,8 @@
 { stdenv, fetchurl, zlib ? null, zlibSupport ? true, bzip2, includeModules ? false
 , sqlite, tcl, tk, xlibsWrapper, openssl, readline, db, ncurses, gdbm, self, callPackage
-, python26Packages }:
+# For the Python package set
+, pkgs, packageOverrides ? (self: super: {})
+}:
 
 assert zlibSupport -> zlib != null;
 
@@ -100,13 +102,16 @@ let
         ${ optionalString includeModules "$out/bin/python ./setup.py build_ext"}
       '';
 
-    passthru = rec {
+    passthru = let
+      pythonPackages = callPackage ../../../../../top-level/python-packages.nix {python=self; overrides=packageOverrides;};
+    in rec {
       inherit libPrefix;
       inherit zlibSupport;
       isPy2 = true;
       isPy26 = true;
       buildEnv = callPackage ../../wrapper.nix { python = self; };
-      withPackages = import ../../with-packages.nix { inherit buildEnv; pythonPackages = python26Packages; };
+      withPackages = import ../../with-packages.nix { inherit buildEnv pythonPackages;};
+      pkgs = pythonPackages;
       executable = libPrefix;
       sitePackages = "lib/${libPrefix}/site-packages";
       interpreter = "${self}/bin/${executable}";
diff --git a/pkgs/development/interpreters/python/cpython/2.7/default.nix b/pkgs/development/interpreters/python/cpython/2.7/default.nix
index a6eeee25be96..4a25382997c3 100644
--- a/pkgs/development/interpreters/python/cpython/2.7/default.nix
+++ b/pkgs/development/interpreters/python/cpython/2.7/default.nix
@@ -10,12 +10,13 @@
 , zlib
 , callPackage
 , self
-, python27Packages
 , gettext
 , db
 , expat
 , libffi
 , CF, configd, coreutils
+# For the Python package set
+, pkgs, packageOverrides ? (self: super: {})
 }:
 
 assert x11Support -> tcl != null
@@ -180,11 +181,14 @@ in stdenv.mkDerivation {
         rm "$out"/lib/python*/plat-*/regen # refers to glibc.dev
       '';
 
-    passthru = rec {
+    passthru = let
+      pythonPackages = callPackage ../../../../../top-level/python-packages.nix {python=self; overrides=packageOverrides;};
+    in rec {
       inherit libPrefix sitePackages x11Support hasDistutilsCxxPatch;
       executable = libPrefix;
       buildEnv = callPackage ../../wrapper.nix { python = self; };
-      withPackages = import ../../with-packages.nix { inherit buildEnv; pythonPackages = python27Packages; };
+      withPackages = import ../../with-packages.nix { inherit buildEnv pythonPackages;};
+      pkgs = pythonPackages;
       isPy2 = true;
       isPy27 = true;
       interpreter = "${self}/bin/${executable}";
diff --git a/pkgs/development/interpreters/python/cpython/3.3/default.nix b/pkgs/development/interpreters/python/cpython/3.3/default.nix
index b25e2ffd0cb1..6a543a8a0ee0 100644
--- a/pkgs/development/interpreters/python/cpython/3.3/default.nix
+++ b/pkgs/development/interpreters/python/cpython/3.3/default.nix
@@ -10,8 +10,9 @@
 , zlib
 , callPackage
 , self
-, python33Packages
 , CF, configd
+# For the Python package set
+, pkgs, packageOverrides ? (self: super: {})
 }:
 
 assert x11Support -> tcl != null
@@ -102,11 +103,14 @@ in stdenv.mkDerivation {
 
   '';
 
-  passthru = rec {
+  passthru = let
+    pythonPackages = callPackage ../../../../../top-level/python-packages.nix {python=self; overrides=packageOverrides;};
+  in rec {
     inherit libPrefix sitePackages x11Support;
     executable = "${libPrefix}m";
     buildEnv = callPackage ../../wrapper.nix { python = self; };
-    withPackages = import ../../with-packages.nix { inherit buildEnv; pythonPackages = python33Packages; };
+    withPackages = import ../../with-packages.nix { inherit buildEnv pythonPackages;};
+    pkgs = pythonPackages;
     isPy3 = true;
     isPy33 = true;
     is_py3k = true;  # deprecated
diff --git a/pkgs/development/interpreters/python/cpython/3.4/default.nix b/pkgs/development/interpreters/python/cpython/3.4/default.nix
index 43edce8a44c2..623fa5d74f64 100644
--- a/pkgs/development/interpreters/python/cpython/3.4/default.nix
+++ b/pkgs/development/interpreters/python/cpython/3.4/default.nix
@@ -10,8 +10,9 @@
 , zlib
 , callPackage
 , self
-, python34Packages
 , CF, configd
+# For the Python package set
+, pkgs, packageOverrides ? (self: super: {})
 }:
 
 assert x11Support -> tcl != null
@@ -111,11 +112,14 @@ in stdenv.mkDerivation {
 
   '';
 
-  passthru = rec {
+  passthru = let
+    pythonPackages = callPackage ../../../../../top-level/python-packages.nix {python=self; overrides=packageOverrides;};
+  in rec {
     inherit libPrefix sitePackages x11Support;
     executable = "${libPrefix}m";
     buildEnv = callPackage ../../wrapper.nix { python = self; };
-    withPackages = import ../../with-packages.nix { inherit buildEnv; pythonPackages = python34Packages; };
+    withPackages = import ../../with-packages.nix { inherit buildEnv pythonPackages;};
+    pkgs = pythonPackages;
     isPy3 = true;
     isPy34 = true;
     is_py3k = true;  # deprecated
diff --git a/pkgs/development/interpreters/python/cpython/3.5/default.nix b/pkgs/development/interpreters/python/cpython/3.5/default.nix
index dd2cce707efe..7172e429f236 100644
--- a/pkgs/development/interpreters/python/cpython/3.5/default.nix
+++ b/pkgs/development/interpreters/python/cpython/3.5/default.nix
@@ -10,8 +10,9 @@
 , zlib
 , callPackage
 , self
-, python35Packages
 , CF, configd
+# For the Python package set
+, pkgs, packageOverrides ? (self: super: {})
 }:
 
 assert x11Support -> tcl != null
@@ -110,11 +111,14 @@ in stdenv.mkDerivation {
     rm $out/lib/python${majorVersion}/__pycache__/_sysconfigdata.cpython*
   '';
 
-  passthru = rec {
+  passthru = let
+    pythonPackages = callPackage ../../../../../top-level/python-packages.nix {python=self; overrides=packageOverrides;};
+  in rec {
     inherit libPrefix sitePackages x11Support;
     executable = "${libPrefix}m";
     buildEnv = callPackage ../../wrapper.nix { python = self; };
-    withPackages = import ../../with-packages.nix { inherit buildEnv; pythonPackages = python35Packages; };
+    withPackages = import ../../with-packages.nix { inherit buildEnv pythonPackages;};
+    pkgs = pythonPackages;
     isPy3 = true;
     isPy35 = true;
     interpreter = "${self}/bin/${executable}";
diff --git a/pkgs/development/interpreters/python/cpython/3.6/default.nix b/pkgs/development/interpreters/python/cpython/3.6/default.nix
index d5960ccde99f..f65989f5bb57 100644
--- a/pkgs/development/interpreters/python/cpython/3.6/default.nix
+++ b/pkgs/development/interpreters/python/cpython/3.6/default.nix
@@ -11,8 +11,9 @@
 , zlib
 , callPackage
 , self
-, python36Packages
 , CF, configd
+# For the Python package set
+, pkgs, packageOverrides ? (self: super: {})
 }:
 
 assert x11Support -> tcl != null
@@ -99,11 +100,14 @@ in stdenv.mkDerivation {
     ln -s "$out/lib/pkgconfig/python3.pc" "$out/lib/pkgconfig/python.pc"
   '';
 
-  passthru = rec {
+  passthru = let
+    pythonPackages = callPackage ../../../../../top-level/python-packages.nix {python=self; overrides=packageOverrides;};
+  in rec {
     inherit libPrefix sitePackages x11Support;
     executable = "${libPrefix}m";
     buildEnv = callPackage ../../wrapper.nix { python = self; };
-    withPackages = import ../../with-packages.nix { inherit buildEnv; pythonPackages = python36Packages; };
+    withPackages = import ../../with-packages.nix { inherit buildEnv pythonPackages;};
+    pkgs = pythonPackages;
     isPy3 = true;
     isPy35 = true;
     is_py3k = true;  # deprecated
diff --git a/pkgs/development/interpreters/python/pypy/2.7/default.nix b/pkgs/development/interpreters/python/pypy/2.7/default.nix
index bce6d19d58d3..1fd9eaee4303 100644
--- a/pkgs/development/interpreters/python/pypy/2.7/default.nix
+++ b/pkgs/development/interpreters/python/pypy/2.7/default.nix
@@ -1,6 +1,9 @@
 { stdenv, fetchurl, zlib ? null, zlibSupport ? true, bzip2, pkgconfig, libffi
 , sqlite, openssl, ncurses, python, expat, tcl, tk, xlibsWrapper, libX11
-, makeWrapper, callPackage, self, pypyPackages, gdbm, db }:
+, makeWrapper, callPackage, self, gdbm, db
+# For the Python package set
+, pkgs, packageOverrides ? (self: super: {})
+}:
 
 assert zlibSupport -> zlib != null;
 
@@ -120,14 +123,17 @@ let
         echo "manylinux1_compatible=False" >> $out/lib/${libPrefix}/_manylinux.py
     '';
 
-    passthru = rec {
+    passthru = let
+      pythonPackages = callPackage ../../../../../top-level/python-packages.nix {python=self; overrides=packageOverrides;};
+    in rec {
       inherit zlibSupport libPrefix;
       executable = "pypy";
       isPypy = true;
       buildEnv = callPackage ../../wrapper.nix { python = self; };
       interpreter = "${self}/bin/${executable}";
       sitePackages = "site-packages";
-      withPackages = import ../../with-packages.nix { inherit buildEnv; pythonPackages = pypyPackages; };
+      withPackages = import ../../with-packages.nix { inherit buildEnv pythonPackages;};
+      pkgs = pythonPackages;
     };
 
     enableParallelBuilding = true;  # almost no parallelization without STM
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index e0b0656a59e7..b3ecfb0d67ad 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -9895,33 +9895,19 @@ in
   # Therefore we do not recurse into attributes here, in contrast to
   # python27Packages. `nix-env -iA python26Packages.nose` works
   # regardless.
-  python26Packages = callPackage ./python-packages.nix {
-    python = python26;
-  };
+  python26Packages = python26.pkgs;
 
-  python27Packages = lib.hiPrioSet (recurseIntoAttrs (callPackage ./python-packages.nix {
-    python = python27;
-  }));
+  python27Packages = lib.hiPrioSet (recurseIntoAttrs python27.pkgs);
 
-  python33Packages = callPackage ./python-packages.nix {
-    python = python33;
-  };
+  python33Packages = python33.pkgs;
 
-  python34Packages = callPackage ./python-packages.nix {
-    python = python34;
-  };
+  python34Packages = python34.pkgs;
 
-  python35Packages = recurseIntoAttrs (callPackage ./python-packages.nix {
-    python = python35;
-  });
+  python35Packages = recurseIntoAttrs python35.pkgs;
 
-  python36Packages = (callPackage ./python-packages.nix {
-    python = python36;
-  });
+  python36Packages = python36.pkgs;
 
-  pypyPackages = callPackage ./python-packages.nix {
-    python = pypy;
-  };
+  pypyPackages = pypy.pkgs;
 
   ### DEVELOPMENT / R MODULES