diff --git a/pkgs/development/python-modules/coincidence/default.nix b/pkgs/development/python-modules/coincidence/default.nix
new file mode 100644
index 000000000000..d0649f5ceaf1
--- /dev/null
+++ b/pkgs/development/python-modules/coincidence/default.nix
@@ -0,0 +1,45 @@
+{
+  lib,
+  buildPythonPackage,
+  fetchFromGitHub,
+  pytest-regressions,
+  pytest-timeout,
+  pytestCheckHook,
+  toml,
+  typing-extensions,
+  whey,
+}:
+
+buildPythonPackage rec {
+  pname = "coincidence";
+  version = "0.6.6";
+  pyproject = true;
+
+  src = fetchFromGitHub {
+    owner = "python-coincidence";
+    repo = "coincidence";
+    tag = "v${version}";
+    hash = "sha256-ktSuUzAwMych6Y2eJWMUfG1a3mGypg8L20f/105RFXc=";
+  };
+
+  build-system = [ whey ];
+
+  dependencies = [ typing-extensions ];
+
+  nativeCheckInputs = [
+    pytest-regressions
+    pytest-timeout
+    pytestCheckHook
+    toml
+  ];
+
+  pythonImportsCheck = [ "coincidence" ];
+
+  meta = {
+    description = "Helper functions for pytest";
+    homepage = "https://github.com/python-coincidence/coincidence";
+    changelog = "https://github.com/python-coincidence/coincidence/releases/tag/${src.tag}";
+    license = lib.licenses.mit;
+    maintainers = with lib.maintainers; [ fab ];
+  };
+}
diff --git a/pkgs/development/python-modules/dom-toml/default.nix b/pkgs/development/python-modules/dom-toml/default.nix
index 3c54e8023d70..8b94a193f4bd 100644
--- a/pkgs/development/python-modules/dom-toml/default.nix
+++ b/pkgs/development/python-modules/dom-toml/default.nix
@@ -1,35 +1,51 @@
 {
-  buildPythonPackage,
-  fetchPypi,
   lib,
-  flit-core,
-  setuptools,
+  attrs,
+  buildPythonPackage,
   domdf-python-tools,
-  tomli,
+  fetchFromGitHub,
+  flit-core,
+  pytestCheckHook,
+  setuptools,
+  tomli-w,
 }:
+
 buildPythonPackage rec {
   pname = "dom-toml";
-  version = "2.1.0";
+  version = "2.2.0";
   pyproject = true;
 
-  src = fetchPypi {
-    inherit version;
-    pname = "dom_toml";
-    hash = "sha256-XMDdEM4lZtNbwdlKbvFsBilx/wMYxvNwWADWHSB1raw=";
+  src = fetchFromGitHub {
+    owner = "domdfcoding";
+    repo = "dom_toml";
+    tag = "v${version}";
+    hash = "sha256-2kO/6spc+y/ltHf493JkSKI0vGuJu2a29fqsW/EDFxE=";
   };
 
   build-system = [ flit-core ];
 
-  nativeBuildInputs = [ setuptools ];
+  dependencies = [ domdf-python-tools ];
 
-  dependencies = [
-    domdf-python-tools
-    tomli
-  ];
+  optional-dependencies = {
+    all = [
+      attrs
+      tomli-w
+    ];
+    config = [
+      attrs
+      tomli-w
+    ];
+  };
+
+  # Circular dependency whey -> domdf-python-tools -> coincidence
+  doCheck = false;
+
+  pythonImportsCheck = [ "dom_toml" ];
 
   meta = {
     description = "Dom's tools for Tom's Obvious, Minimal Language";
     homepage = "https://github.com/domdfcoding/dom_toml";
+    changelog = "https://github.com/domdfcoding/dom_toml/releases/tag/${src.tag}";
     license = lib.licenses.mit;
     maintainers = with lib.maintainers; [ tyberius-prime ];
   };
diff --git a/pkgs/development/python-modules/whey/default.nix b/pkgs/development/python-modules/whey/default.nix
index 415bd2a09023..894572461032 100644
--- a/pkgs/development/python-modules/whey/default.nix
+++ b/pkgs/development/python-modules/whey/default.nix
@@ -76,6 +76,7 @@ buildPythonPackage rec {
   meta = {
     description = "Simple Python wheel builder for simple projects";
     homepage = "https://github.com/repo-helper/whey";
+    changelog = "https://github.com/repo-helper/whey/releases/tag/${src.tag}";
     license = lib.licenses.mit;
     maintainers = with lib.maintainers; [ tyberius-prime ];
   };
diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index 73218fa9dca5..0acb8b188d10 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -2892,6 +2892,8 @@ self: super: with self; {
 
   coinbase-advanced-py = callPackage ../development/python-modules/coinbase-advanced-py { };
 
+  coincidence = callPackage ../development/python-modules/coincidence { };
+
   coincurve = callPackage ../development/python-modules/coincurve { inherit (pkgs) secp256k1; };
 
   coinmetrics-api-client = callPackage ../development/python-modules/coinmetrics-api-client { };