diff --git a/pkgs/development/python-modules/karton-classifier/default.nix b/pkgs/development/python-modules/karton-classifier/default.nix
index 8195632bdfd4..bcf4b075dfaf 100644
--- a/pkgs/development/python-modules/karton-classifier/default.nix
+++ b/pkgs/development/python-modules/karton-classifier/default.nix
@@ -10,7 +10,8 @@
 
 buildPythonPackage rec {
   pname = "karton-classifier";
-  version = "1.2.0";
+  version = "1.4.0";
+  format = "setuptools";
 
   disabled = pythonOlder "3.7";
 
@@ -18,7 +19,7 @@ buildPythonPackage rec {
     owner = "CERT-Polska";
     repo = pname;
     rev = "v${version}";
-    sha256 = "sha256-AG2CtNMgXYfbdlOqB1ZdjMT8H67fsSMXTgiFg6K41IQ=";
+    hash = "sha256-TRmAin0TAOIwR5EBMwTOJ9QaHO+mOx/eAjgqvyQZDj4=";
   };
 
   propagatedBuildInputs = [
@@ -27,17 +28,25 @@ buildPythonPackage rec {
     python-magic
   ];
 
+  checkInputs = [
+    pytestCheckHook
+  ];
+
   postPatch = ''
     substituteInPlace requirements.txt \
       --replace "chardet==3.0.4" "chardet" \
       --replace "python-magic==0.4.18" "python-magic"
   '';
 
-  checkInputs = [
-    pytestCheckHook
+  pythonImportsCheck = [
+    "karton.classifier"
   ];
 
-  pythonImportsCheck = [ "karton.classifier" ];
+  disabledTests = [
+    # Tests expecting results from a different version of libmagic
+    "test_process_archive_ace"
+    "test_process_runnable_win32_lnk"
+  ];
 
   meta = with lib; {
     description = "File type classifier for the Karton framework";