diff --git a/pkgs/development/python-modules/asn1/2.nix b/pkgs/development/python-modules/asn1/2.nix
new file mode 100644
index 0000000000000..d2591c4f9a06e
--- /dev/null
+++ b/pkgs/development/python-modules/asn1/2.nix
@@ -0,0 +1,42 @@
+{
+  lib,
+  buildPythonPackage,
+  fetchFromGitHub,
+  pytestCheckHook,
+  setuptools,
+}:
+
+buildPythonPackage rec {
+  pname = "asn1";
+  version = "2.8.0";
+  pyproject = true;
+
+  src = fetchFromGitHub {
+    owner = "andrivet";
+    repo = "python-asn1";
+    tag = "v${version}";
+    hash = "sha256-DLKfdQzYLhfaIEPPymTzRqj3+L/fsm5Jh8kqud/ezfw=";
+  };
+
+  build-system = [ setuptools ];
+
+  pythonRemoveDeps = [ "enum-compat" ];
+
+  nativeCheckInputs = [ pytestCheckHook ];
+
+  enabledTestPaths = [ "tests/test_asn1.py" ];
+
+  pythonImportsCheck = [ "asn1" ];
+
+  meta = {
+    description = "Python ASN.1 encoder and decoder";
+    longDescription = ''
+      Kept for consumers that cannot use asn1 3.x, where Decoder.read() returns
+      recursively decoded values for constructed tags instead of the raw contents.
+    '';
+    homepage = "https://github.com/andrivet/python-asn1";
+    changelog = "https://github.com/andrivet/python-asn1/blob/${src.tag}/CHANGELOG.rst";
+    license = lib.licenses.mit;
+    maintainers = with lib.maintainers; [ fab ];
+  };
+}
diff --git a/pkgs/development/python-modules/pyimg4/default.nix b/pkgs/development/python-modules/pyimg4/default.nix
index 2afacff46928f..6ace5ef027e5c 100644
--- a/pkgs/development/python-modules/pyimg4/default.nix
+++ b/pkgs/development/python-modules/pyimg4/default.nix
@@ -1,6 +1,6 @@
 {
   apple-compress,
-  asn1,
+  asn1_2,
   buildPythonPackage,
   click,
   fetchFromGitHub,
@@ -37,7 +37,8 @@ buildPythonPackage rec {
   ];
 
   dependencies = [
-    asn1
+    # upstream pins asn1<3.0.0: https://github.com/m1stadev/PyIMG4/pull/59
+    asn1_2
     click
     pycryptodome
     pylzss
@@ -66,8 +67,6 @@ buildPythonPackage rec {
   ];
 
   meta = {
-    # https://github.com/m1stadev/PyIMG4/pull/59
-    broken = lib.versionAtLeast asn1.version "3";
     changelog = "https://github.com/m1stadev/PyIMG4/releases/tag/${src.tag}";
     description = "Python library/CLI tool for parsing Apple's Image4 format";
     homepage = "https://github.com/m1stadev/PyIMG4";
diff --git a/pkgs/development/python-modules/smart-meter-texas/default.nix b/pkgs/development/python-modules/smart-meter-texas/default.nix
index 623ac30c6a81f..d2551a350cec8 100644
--- a/pkgs/development/python-modules/smart-meter-texas/default.nix
+++ b/pkgs/development/python-modules/smart-meter-texas/default.nix
@@ -3,7 +3,7 @@
   buildPythonPackage,
   fetchFromGitHub,
   aiohttp,
-  asn1,
+  asn1_2,
   python-dateutil,
   setuptools,
   tenacity,
@@ -30,7 +30,9 @@ buildPythonPackage rec {
 
   dependencies = [
     aiohttp
-    asn1
+    # _find_ca_issuers_uri() recurses with enter()/leave() and loops on eof(),
+    # which is only container-relative in asn1 2.x
+    asn1_2
     python-dateutil
     tenacity
   ];
diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index 268e12aa78c09..6420255f810e8 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -1399,6 +1399,8 @@ self: super: with self; {
 
   asn1 = callPackage ../development/python-modules/asn1 { };
 
+  asn1_2 = callPackage ../development/python-modules/asn1/2.nix { };
+
   asn1ate = callPackage ../development/python-modules/asn1ate { };
 
   asn1crypto = callPackage ../development/python-modules/asn1crypto { };