diff --git a/pkgs/development/python-modules/deal/default.nix b/pkgs/development/python-modules/deal/default.nix
index 5f887848453b..b9e050187dba 100644
--- a/pkgs/development/python-modules/deal/default.nix
+++ b/pkgs/development/python-modules/deal/default.nix
@@ -6,16 +6,13 @@
 , astroid
 , pytestCheckHook
 , docstring-parser
-, isort
 , marshmallow
-, pytest-cov
 , sphinx
 , hypothesis
 , vaa
 , deal-solver
 , pygments
 , typeguard
-, coverage
 , urllib3
 }:
 
diff --git a/pkgs/development/python-modules/icontract/default.nix b/pkgs/development/python-modules/icontract/default.nix
index cadd8f34cc62..41bd796372d1 100644
--- a/pkgs/development/python-modules/icontract/default.nix
+++ b/pkgs/development/python-modules/icontract/default.nix
@@ -15,6 +15,7 @@
 , astor
 , numpy
 , asyncstdlib
+, deal
 }:
 
 buildPythonPackage rec {
@@ -55,12 +56,10 @@ buildPythonPackage rec {
     astor
     numpy
     asyncstdlib
+    deal
   ];
 
   disabledTestPaths = [
-    # needs an old version of deal to comply with the tests
-    # see https://github.com/Parquery/icontract/issues/244
-    "tests_with_others/test_deal.py"
     # mypy decorator checks don't pass. For some reaseon mypy
     # doesn't check the python file provided in the test.
     "tests/test_mypy_decorators.py"
diff --git a/pkgs/development/python-modules/pyschemes/default.nix b/pkgs/development/python-modules/pyschemes/default.nix
index c7034d11cdca..3b7eaa0da421 100644
--- a/pkgs/development/python-modules/pyschemes/default.nix
+++ b/pkgs/development/python-modules/pyschemes/default.nix
@@ -1,8 +1,8 @@
 { lib
 , buildPythonPackage
 , fetchFromGitHub
-, pythonAtLeast
 , pytestCheckHook
+, fetchpatch
 }:
 
 buildPythonPackage rec {
@@ -10,8 +10,6 @@ buildPythonPackage rec {
   version = "unstable-2017-11-08";
   format = "setuptools";
 
-  disabled = pythonAtLeast "3.10";
-
   src = fetchFromGitHub {
     owner = "spy16";
     repo = pname;
@@ -19,6 +17,14 @@ buildPythonPackage rec {
     hash = "sha256-PssucudvlE8mztwVme70+h+2hRW/ri9oV9IZayiZhdU=";
   };
 
+  patches = [
+    # Fix python 3.10 compatibility. Tracked upstream in
+    # https://github.com/spy16/pyschemes/pull/6
+    (fetchpatch {
+      url = "https://github.com/spy16/pyschemes/commit/23011128c6c22838d4fca9e00fd322a20bb566c4.patch";
+      sha256 = "sha256-vDaWxMrn2aC2wmd035EWRZ3cd/XME81z/BWG0f2T9jc=";
+    })
+  ];
   checkInputs = [
     pytestCheckHook
   ];