diff --git a/pkgs/development/python-modules/distrax/default.nix b/pkgs/development/python-modules/distrax/default.nix
index cc667cc6bf19..bdd443356a8c 100644
--- a/pkgs/development/python-modules/distrax/default.nix
+++ b/pkgs/development/python-modules/distrax/default.nix
@@ -82,5 +82,8 @@ buildPythonPackage rec {
     homepage = "https://github.com/deepmind/distrax";
     license = licenses.asl20;
     maintainers = with maintainers; [ onny ];
+    # Several tests fail with:
+    # AssertionError: [Chex] Assertion assert_type failed: Error in type compatibility check
+    broken = true;
   };
 }
diff --git a/pkgs/development/python-modules/equinox/default.nix b/pkgs/development/python-modules/equinox/default.nix
index 92ce388c8765..e679e15d9704 100644
--- a/pkgs/development/python-modules/equinox/default.nix
+++ b/pkgs/development/python-modules/equinox/default.nix
@@ -47,6 +47,11 @@ buildPythonPackage rec {
 
   pythonImportsCheck = [ "equinox" ];
 
+  disabledTests = [
+    # Failed: DID NOT WARN. No warnings of type (<class 'UserWarning'>,) were emitted.
+    "test_tracetime"
+  ];
+
   meta = with lib; {
     description = "A JAX library based around a simple idea: represent parameterised functions (such as neural networks) as PyTrees";
     changelog = "https://github.com/patrick-kidger/equinox/releases/tag/v${version}";
diff --git a/pkgs/development/python-modules/flax/default.nix b/pkgs/development/python-modules/flax/default.nix
index c7fc681955a3..ce41f8e56139 100644
--- a/pkgs/development/python-modules/flax/default.nix
+++ b/pkgs/development/python-modules/flax/default.nix
@@ -25,16 +25,16 @@
 
 buildPythonPackage rec {
   pname = "flax";
-  version = "0.8.1";
+  version = "0.8.2";
   pyproject = true;
 
-  disabled = pythonOlder "3.8";
+  disabled = pythonOlder "3.9";
 
   src = fetchFromGitHub {
     owner = "google";
     repo = "flax";
     rev = "refs/tags/v${version}";
-    hash = "sha256-3UzMSJoKw+V1WLBJ+Zf7aF7CDNBsvWnRUfNgb3K4v1A=";
+    hash = "sha256-UABgJGe1grUSkwOJpjeIoFqhXsqG//HlC1YyYPxXV+g=";
   };
 
   nativeBuildInputs = [
@@ -87,6 +87,7 @@ buildPythonPackage rec {
     # `tensorflow_datasets`, `vocabulary`) so the benefits of trying to run them
     # would be limited anyway.
     "examples/*"
+    "flax/experimental/nnx/examples/*"
     # See https://github.com/google/flax/issues/3232.
     "tests/jax_utils_test.py"
     # Requires tree
diff --git a/pkgs/development/python-modules/optax/default.nix b/pkgs/development/python-modules/optax/default.nix
index dd36a90864f2..950e9c91dbf5 100644
--- a/pkgs/development/python-modules/optax/default.nix
+++ b/pkgs/development/python-modules/optax/default.nix
@@ -1,6 +1,7 @@
 { lib
 , absl-py
 , buildPythonPackage
+, flit-core
 , chex
 , fetchFromGitHub
 , jaxlib
@@ -11,16 +12,16 @@
 
 buildPythonPackage rec {
   pname = "optax";
-  version = "0.2.1";
-  format = "setuptools";
+  version = "0.2.2";
+  pyproject = true;
 
-  disabled = pythonOlder "3.7";
+  disabled = pythonOlder "3.9";
 
   src = fetchFromGitHub {
     owner = "deepmind";
-    repo = pname;
+    repo = "optax";
     rev = "refs/tags/v${version}";
-    hash = "sha256-vimsVZV5Z11euLxsu998pMQZ0hG3xl96D3h9iONtl/E=";
+    hash = "sha256-sBiKUuQR89mttc9Njrh1aeUJOYdlcF7Nlj3/+Y7OMb4=";
   };
 
   outputs = [
@@ -28,6 +29,10 @@ buildPythonPackage rec {
     "testsout"
   ];
 
+  nativeBuildInputs = [
+    flit-core
+  ];
+
   buildInputs = [
     jaxlib
   ];