diff --git a/pkgs/by-name/pr/pretix/package.nix b/pkgs/by-name/pr/pretix/package.nix
index 53955e458589..4ce7fb727422 100644
--- a/pkgs/by-name/pr/pretix/package.nix
+++ b/pkgs/by-name/pr/pretix/package.nix
@@ -95,6 +95,7 @@ python.pkgs.buildPythonApplication rec {
 
   pythonRelaxDeps = [
     "importlib-metadata"
+    "kombu"
     "pillow"
     "protobuf"
     "python-bidi"
diff --git a/pkgs/development/python-modules/celery/default.nix b/pkgs/development/python-modules/celery/default.nix
index 9e52b75e59af..abdc5fb184e4 100644
--- a/pkgs/development/python-modules/celery/default.nix
+++ b/pkgs/development/python-modules/celery/default.nix
@@ -1,39 +1,31 @@
 {
-  stdenv,
   lib,
-  buildPythonPackage,
-  fetchPypi,
-  pythonOlder,
-
-  # build-system
-  setuptools,
-
-  # dependencies
+  stdenv,
   billiard,
-  kombu,
-  vine,
-  click,
+  buildPythonPackage,
   click-didyoumean,
-  click-repl,
   click-plugins,
-  tzdata,
-  python-dateutil,
-
-  # optional-dependencies
+  click-repl,
+  click,
+  fetchPypi,
   google-cloud-storage,
+  kombu,
   moto,
   msgpack,
+  nixosTests,
   pymongo,
-  pyyaml,
-
-  # tests
   pytest-celery,
   pytest-click,
   pytest-subtests,
   pytest-timeout,
   pytest-xdist,
   pytestCheckHook,
-  nixosTests,
+  python-dateutil,
+  pythonOlder,
+  pyyaml,
+  setuptools,
+  tzdata,
+  vine,
 }:
 
 buildPythonPackage rec {
@@ -62,28 +54,22 @@ buildPythonPackage rec {
     vine
   ];
 
-  optional-dependencies = {
+  passthru.optional-dependencies = {
     gcs = [ google-cloud-storage ];
     mongodb = [ pymongo ];
     msgpack = [ msgpack ];
     yaml = [ pyyaml ];
   };
 
-  nativeCheckInputs =
-    [
-      moto
-      pytest-celery
-      pytest-click
-      pytest-subtests
-      pytest-timeout
-      pytest-xdist
-      pytestCheckHook
-    ]
-    # based on https://github.com/celery/celery/blob/main/requirements/test.txt
-    ++ optional-dependencies.yaml
-    ++ optional-dependencies.msgpack
-    ++ optional-dependencies.mongodb
-    ++ optional-dependencies.gcs;
+  nativeCheckInputs = [
+    moto
+    pytest-celery
+    pytest-click
+    pytest-subtests
+    pytest-timeout
+    pytest-xdist
+    pytestCheckHook
+  ] ++ lib.flatten (builtins.attrValues passthru.optional-dependencies);
 
   disabledTestPaths = [
     # test_eventlet touches network
@@ -91,7 +77,7 @@ buildPythonPackage rec {
     # test_multi tries to create directories under /var
     "t/unit/bin/test_multi.py"
     "t/unit/apps/test_multi.py"
-    # requires moto<5
+    # Test requires moto<5
     "t/unit/backends/test_s3.py"
   ];
 
@@ -102,13 +88,15 @@ buildPythonPackage rec {
       # seems to only fail on higher core counts
       # AssertionError: assert 3 == 0
       "test_setup_security_disabled_serializers"
-      # fails with pytest-xdist
+      # Test is flaky, especially on hydra
+      "test_ready"
+      # Tests fail with pytest-xdist
       "test_itercapture_limit"
       "test_stamping_headers_in_options"
       "test_stamping_with_replace"
     ]
     ++ lib.optionals stdenv.isDarwin [
-      # too many open files on hydra
+      # Too many open files on hydra
       "test_cleanup"
       "test_with_autoscaler_file_descriptor_safety"
       "test_with_file_descriptor_safety"
@@ -122,10 +110,10 @@ buildPythonPackage rec {
 
   meta = with lib; {
     description = "Distributed task queue";
-    mainProgram = "celery";
     homepage = "https://github.com/celery/celery/";
     changelog = "https://github.com/celery/celery/releases/tag/v${version}";
     license = licenses.bsd3;
     maintainers = with maintainers; [ fab ];
+    mainProgram = "celery";
   };
 }
diff --git a/pkgs/development/python-modules/kombu/default.nix b/pkgs/development/python-modules/kombu/default.nix
index 2170ba9e966c..187d5a8bbba4 100644
--- a/pkgs/development/python-modules/kombu/default.nix
+++ b/pkgs/development/python-modules/kombu/default.nix
@@ -27,14 +27,14 @@
 
 buildPythonPackage rec {
   pname = "kombu";
-  version = "5.3.7";
+  version = "5.4.0";
   format = "setuptools";
 
   disabled = pythonOlder "3.8";
 
   src = fetchPypi {
     inherit pname version;
-    hash = "sha256-ARxM2aNVwUod6NNdJXMUodJFbVK3FAOIVhrKw88al78=";
+    hash = "sha256-rSAKjb2qorvF8m0u59cH2aH97TU6D0vXUc6MfZ9EnGA=";
   };
 
   propagatedBuildInputs =