diff --git a/pkgs/development/interpreters/python/cpython/2.7/default.nix b/pkgs/development/interpreters/python/cpython/2.7/default.nix
index 8426902414a7..c5fa05651bbe 100644
--- a/pkgs/development/interpreters/python/cpython/2.7/default.nix
+++ b/pkgs/development/interpreters/python/cpython/2.7/default.nix
@@ -15,6 +15,7 @@
 , expat
 , libffi
 , CF, configd, coreutils
+, python-setup-hook
 # For the Python package set
 , pkgs, packageOverrides ? (self: super: {})
 }:
@@ -150,7 +151,7 @@ in stdenv.mkDerivation {
     NIX_CFLAGS_COMPILE = optionalString stdenv.isDarwin "-msse2";
     DETERMINISTIC_BUILD = 1;
 
-    setupHook = ./setup-hook.sh;
+    setupHook = python-setup-hook sitePackages;
 
     postPatch = optionalString (x11Support && (tix != null)) ''
           substituteInPlace "Lib/lib-tk/Tix.py" --replace "os.environ.get('TIX_LIBRARY')" "os.environ.get('TIX_LIBRARY') or '${tix}/lib'"
diff --git a/pkgs/development/interpreters/python/cpython/2.7/setup-hook.sh b/pkgs/development/interpreters/python/cpython/2.7/setup-hook.sh
deleted file mode 100644
index 4770eea886f6..000000000000
--- a/pkgs/development/interpreters/python/cpython/2.7/setup-hook.sh
+++ /dev/null
@@ -1,15 +0,0 @@
-addPythonPath() {
-    addToSearchPathWithCustomDelimiter : PYTHONPATH $1/lib/python2.7/site-packages
-}
-
-toPythonPath() {
-    local paths="$1"
-    local result=
-    for i in $paths; do
-        p="$i/lib/python2.7/site-packages"
-        result="${result}${result:+:}$p"
-    done
-    echo $result
-}
-
-envHooks+=(addPythonPath)
diff --git a/pkgs/development/interpreters/python/cpython/3.3/default.nix b/pkgs/development/interpreters/python/cpython/3.3/default.nix
index c561a1ed750a..061176335c4f 100644
--- a/pkgs/development/interpreters/python/cpython/3.3/default.nix
+++ b/pkgs/development/interpreters/python/cpython/3.3/default.nix
@@ -77,7 +77,7 @@ in stdenv.mkDerivation {
                         )
   '';
 
-  setupHook = ./setup-hook.sh;
+  setupHook = python-setup-hook sitePackages;
 
   postInstall = ''
     # needed for some packages, especially packages that backport functionality
diff --git a/pkgs/development/interpreters/python/cpython/3.3/setup-hook.sh b/pkgs/development/interpreters/python/cpython/3.3/setup-hook.sh
deleted file mode 100644
index 82a8c0abd32f..000000000000
--- a/pkgs/development/interpreters/python/cpython/3.3/setup-hook.sh
+++ /dev/null
@@ -1,15 +0,0 @@
-addPythonPath() {
-    addToSearchPathWithCustomDelimiter : PYTHONPATH $1/lib/python3.3/site-packages
-}
-
-toPythonPath() {
-    local paths="$1"
-    local result=
-    for i in $paths; do
-        p="$i/lib/python3.3/site-packages"
-        result="${result}${result:+:}$p"
-    done
-    echo $result
-}
-
-envHooks+=(addPythonPath)
diff --git a/pkgs/development/interpreters/python/cpython/3.4/default.nix b/pkgs/development/interpreters/python/cpython/3.4/default.nix
index b2a4d849c942..4d20a21a4d13 100644
--- a/pkgs/development/interpreters/python/cpython/3.4/default.nix
+++ b/pkgs/development/interpreters/python/cpython/3.4/default.nix
@@ -13,6 +13,7 @@
 , callPackage
 , self
 , CF, configd
+, python-setup-hook
 # For the Python package set
 , pkgs, packageOverrides ? (self: super: {})
 }:
@@ -100,7 +101,7 @@ in stdenv.mkDerivation {
      ''}
   '';
 
-  setupHook = ./setup-hook.sh;
+  setupHook = python-setup-hook sitePackages;
 
   postInstall = ''
     # needed for some packages, especially packages that backport functionality
diff --git a/pkgs/development/interpreters/python/cpython/3.4/setup-hook.sh b/pkgs/development/interpreters/python/cpython/3.4/setup-hook.sh
deleted file mode 100644
index fddcc0b73fe8..000000000000
--- a/pkgs/development/interpreters/python/cpython/3.4/setup-hook.sh
+++ /dev/null
@@ -1,15 +0,0 @@
-addPythonPath() {
-    addToSearchPathWithCustomDelimiter : PYTHONPATH $1/lib/python3.4/site-packages
-}
-
-toPythonPath() {
-    local paths="$1"
-    local result=
-    for i in $paths; do
-        p="$i/lib/python3.4/site-packages"
-        result="${result}${result:+:}$p"
-    done
-    echo $result
-}
-
-envHooks+=(addPythonPath)
diff --git a/pkgs/development/interpreters/python/cpython/3.5/default.nix b/pkgs/development/interpreters/python/cpython/3.5/default.nix
index 76f445f7a509..a4aec241a1aa 100644
--- a/pkgs/development/interpreters/python/cpython/3.5/default.nix
+++ b/pkgs/development/interpreters/python/cpython/3.5/default.nix
@@ -13,6 +13,7 @@
 , callPackage
 , self
 , CF, configd
+, python-setup-hook
 # For the Python package set
 , pkgs, packageOverrides ? (self: super: {})
 }:
@@ -102,7 +103,7 @@ in stdenv.mkDerivation {
      ''}
   '';
 
-  setupHook = ./setup-hook.sh;
+  setupHook = python-setup-hook sitePackages;
 
   postInstall = ''
     # needed for some packages, especially packages that backport functionality
diff --git a/pkgs/development/interpreters/python/cpython/3.5/setup-hook.sh b/pkgs/development/interpreters/python/cpython/3.5/setup-hook.sh
deleted file mode 100644
index 2836ad7e8f56..000000000000
--- a/pkgs/development/interpreters/python/cpython/3.5/setup-hook.sh
+++ /dev/null
@@ -1,15 +0,0 @@
-addPythonPath() {
-    addToSearchPathWithCustomDelimiter : PYTHONPATH $1/lib/python3.5/site-packages
-}
-
-toPythonPath() {
-    local paths="$1"
-    local result=
-    for i in $paths; do
-        p="$i/lib/python3.5/site-packages"
-        result="${result}${result:+:}$p"
-    done
-    echo $result
-}
-
-envHooks+=(addPythonPath)
diff --git a/pkgs/development/interpreters/python/cpython/3.6/default.nix b/pkgs/development/interpreters/python/cpython/3.6/default.nix
index 150786191669..d2d922ce4955 100644
--- a/pkgs/development/interpreters/python/cpython/3.6/default.nix
+++ b/pkgs/development/interpreters/python/cpython/3.6/default.nix
@@ -14,6 +14,7 @@
 , callPackage
 , self
 , CF, configd
+, python-setup-hook
 # For the Python package set
 , pkgs, packageOverrides ? (self: super: {})
 }:
@@ -94,7 +95,7 @@ in stdenv.mkDerivation {
      ''}
   '';
 
-  setupHook = ./setup-hook.sh;
+  setupHook = python-setup-hook sitePackages;
 
   postInstall = ''
     # needed for some packages, especially packages that backport functionality
diff --git a/pkgs/development/interpreters/python/cpython/3.6/setup-hook.sh b/pkgs/development/interpreters/python/cpython/3.6/setup-hook.sh
deleted file mode 100644
index 26a0d57bc87c..000000000000
--- a/pkgs/development/interpreters/python/cpython/3.6/setup-hook.sh
+++ /dev/null
@@ -1,15 +0,0 @@
-addPythonPath() {
-    addToSearchPathWithCustomDelimiter : PYTHONPATH $1/lib/python3.6/site-packages
-}
-
-toPythonPath() {
-    local paths="$1"
-    local result=
-    for i in $paths; do
-        p="$i/lib/python3.6/site-packages"
-        result="${result}${result:+:}$p"
-    done
-    echo $result
-}
-
-envHooks+=(addPythonPath)
diff --git a/pkgs/development/interpreters/python/mk-python-derivation.nix b/pkgs/development/interpreters/python/mk-python-derivation.nix
index 5d710fcad882..1a388bfe4afa 100644
--- a/pkgs/development/interpreters/python/mk-python-derivation.nix
+++ b/pkgs/development/interpreters/python/mk-python-derivation.nix
@@ -57,13 +57,6 @@ python.stdenv.mkDerivation (builtins.removeAttrs attrs ["disabled"] // {
 
   inherit pythonPath;
 
-
-  # Determinism: The interpreter is patched to write null timestamps when compiling python files.
-  # This way python doesn't try to update them when we freeze timestamps in nix store.
-  DETERMINISTIC_BUILD=1;
-  # Determinism: We fix the hashes of str, bytes and datetime objects.
-  PYTHONHASHSEED = 0;
-
   buildInputs = [ wrapPython ] ++ buildInputs ++ pythonPath
     ++ [ (ensureNewerSourcesHook { year = "1980"; }) ]
     ++ (lib.optional (lib.hasSuffix "zip" attrs.src.name or "") unzip)
diff --git a/pkgs/development/interpreters/python/pypy/2.7/default.nix b/pkgs/development/interpreters/python/pypy/2.7/default.nix
index 456a078874cd..7552c6cd2853 100644
--- a/pkgs/development/interpreters/python/pypy/2.7/default.nix
+++ b/pkgs/development/interpreters/python/pypy/2.7/default.nix
@@ -1,6 +1,7 @@
 { stdenv, fetchurl, zlib ? null, zlibSupport ? true, bzip2, pkgconfig, libffi
 , sqlite, openssl, ncurses, python, expat, tcl, tk, tix, xlibsWrapper, libX11
 , makeWrapper, callPackage, self, gdbm, db
+, python-setup-hook
 # For the Python package set
 , pkgs, packageOverrides ? (self: super: {})
 }:
@@ -14,6 +15,7 @@ let
   pythonVersion = "2.7";
   version = "${majorVersion}.${minorVersion}${minorVersionSuffix}";
   libPrefix = "pypy${majorVersion}";
+  sitePackages = "site-packages";
 
 in stdenv.mkDerivation rec {
     name = "pypy-${version}";
@@ -67,7 +69,7 @@ in stdenv.mkDerivation rec {
       ${python.interpreter} rpython/bin/rpython --make-jobs="$NIX_BUILD_CORES" -Ojit --batch pypy/goal/targetpypystandalone.py --withmod-_minimal_curses --withmod-unicodedata --withmod-thread --withmod-bz2 --withmod-_multiprocessing
     '';
 
-    setupHook = ./setup-hook.sh;
+    setupHook = python-setup-hook sitePackages;
 
     postBuild = ''
       cd ./lib_pypy
@@ -125,12 +127,11 @@ in stdenv.mkDerivation rec {
     passthru = let
       pythonPackages = callPackage ../../../../../top-level/python-packages.nix {python=self; overrides=packageOverrides;};
     in rec {
-      inherit zlibSupport libPrefix;
+      inherit zlibSupport libPrefix sitePackages;
       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;};
       pkgs = pythonPackages;
     };
diff --git a/pkgs/development/interpreters/python/pypy/2.7/setup-hook.sh b/pkgs/development/interpreters/python/pypy/2.7/setup-hook.sh
deleted file mode 100644
index e9081d1eaa53..000000000000
--- a/pkgs/development/interpreters/python/pypy/2.7/setup-hook.sh
+++ /dev/null
@@ -1,15 +0,0 @@
-addPythonPath() {
-    addToSearchPathWithCustomDelimiter : PYTHONPATH $1/site-packages
-}
-
-toPythonPath() {
-    local paths="$1"
-    local result=
-    for i in $paths; do
-        p="$i/site-packages"
-        result="${result}${result:+:}$p"
-    done
-    echo $result
-}
-
-envHooks+=(addPythonPath)
diff --git a/pkgs/development/interpreters/python/setup-hook.nix b/pkgs/development/interpreters/python/setup-hook.nix
new file mode 100644
index 000000000000..b66bd1cc5f69
--- /dev/null
+++ b/pkgs/development/interpreters/python/setup-hook.nix
@@ -0,0 +1,13 @@
+{ runCommand }:
+
+sitePackages:
+
+let
+  hook = ./setup-hook.sh;
+in runCommand "python-setup-hook.sh" {
+  inherit sitePackages;
+} ''
+  cp ${hook} hook.sh
+  substituteAllInPlace hook.sh
+  mv hook.sh $out
+''
diff --git a/pkgs/development/interpreters/python/setup-hook.sh b/pkgs/development/interpreters/python/setup-hook.sh
new file mode 100644
index 000000000000..dda9bed39f85
--- /dev/null
+++ b/pkgs/development/interpreters/python/setup-hook.sh
@@ -0,0 +1,21 @@
+addPythonPath() {
+    addToSearchPathWithCustomDelimiter : PYTHONPATH $1/@sitePackages@
+}
+
+toPythonPath() {
+    local paths="$1"
+    local result=
+    for i in $paths; do
+        p="$i/@sitePackages@"
+        result="${result}${result:+:}$p"
+    done
+    echo $result
+}
+
+envHooks+=(addPythonPath)
+
+# Determinism: The interpreter is patched to write null timestamps when compiling python files.
+# This way python doesn't try to update them when we freeze timestamps in nix store.
+export DETERMINISTIC_BUILD=1;
+# Determinism: We fix the hashes of str, bytes and datetime objects.
+export PYTHONHASHSEED=0;
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index eba258e2f9bd..3e0e4ba200de 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -6207,6 +6207,9 @@ with pkgs;
     self = python36;
   };
 
+  # Should eventually be moved inside Python interpreters.
+  python-setup-hook = callPackage ../development/interpreters/python/setup-hook.nix { };
+
   pypy = pypy27;
 
   pypy27 = callPackage ../development/interpreters/python/pypy/2.7 {