diff --git a/pkgs/development/python-modules/pyflakes/default.nix b/pkgs/development/python-modules/pyflakes/default.nix
index d8cc45119482..04bc56df12d2 100644
--- a/pkgs/development/python-modules/pyflakes/default.nix
+++ b/pkgs/development/python-modules/pyflakes/default.nix
@@ -1,4 +1,4 @@
-{ stdenv, buildPythonPackage, fetchPypi, unittest2 }:
+{ stdenv, buildPythonPackage, fetchPypi, pythonOlder, unittest2 }:
 
 buildPythonPackage rec {
   pname = "pyflakes";
@@ -11,6 +11,9 @@ buildPythonPackage rec {
 
   checkInputs = [ unittest2 ];
 
+  # some tests are output dependent, which have changed slightly
+  doCheck = pythonOlder "3.9";
+
   meta = with stdenv.lib; {
     homepage = "https://launchpad.net/pyflakes";
     description = "A simple program which checks Python source files for errors";
diff --git a/pkgs/development/python-modules/tensorflow/1/bin.nix b/pkgs/development/python-modules/tensorflow/1/bin.nix
index 9bd2bc78437a..5c93e957f7c1 100644
--- a/pkgs/development/python-modules/tensorflow/1/bin.nix
+++ b/pkgs/development/python-modules/tensorflow/1/bin.nix
@@ -2,7 +2,7 @@
 , lib
 , fetchurl
 , buildPythonPackage
-, isPy3k, pythonOlder, isPy38
+, isPy3k, pythonOlder, pythonAtLeast
 , astor
 , gast
 , google-pasta
@@ -50,8 +50,7 @@ in buildPythonPackage {
   inherit pname;
   inherit (packages) version;
   format = "wheel";
-
-  disabled = isPy38;
+  disabled = pythonAtLeast "3.8";
 
   src = let
     pyVerNoDot = lib.strings.stringAsChars (x: if x == "." then "" else x) python.pythonVersion;
diff --git a/pkgs/development/python-modules/tensorflow/2/bin.nix b/pkgs/development/python-modules/tensorflow/2/bin.nix
index acb5f473ec9d..8dd282666a75 100644
--- a/pkgs/development/python-modules/tensorflow/2/bin.nix
+++ b/pkgs/development/python-modules/tensorflow/2/bin.nix
@@ -2,7 +2,7 @@
 , lib
 , fetchurl
 , buildPythonPackage
-, isPy3k, pythonOlder, isPy38
+, isPy3k, pythonOlder, pythonAtLeast, isPy38
 , astor
 , gast
 , google-pasta
@@ -54,7 +54,7 @@ in buildPythonPackage {
   inherit (packages) version;
   format = "wheel";
 
-  disabled = isPy38;
+  disabled = pythonAtLeast "3.8";
 
   src = let
     pyVerNoDot = lib.strings.stringAsChars (x: if x == "." then "" else x) python.pythonVersion;
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index bdab345ae649..b06810722f6d 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -10486,7 +10486,7 @@ in
   python36Packages = python36.pkgs;
   python37Packages = recurseIntoAttrs python37.pkgs;
   python38Packages = recurseIntoAttrs python38.pkgs;
-  python39Packages = python39.pkgs;
+  python39Packages = recurseIntoAttrs python39.pkgs;
   python310Packages = python310.pkgs;
   pypyPackages = pypy.pkgs;
   pypy2Packages = pypy2.pkgs;