diff --git a/pkgs/development/python-modules/malduck/default.nix b/pkgs/development/python-modules/malduck/default.nix
index 1da685cd6a6b..058aa0d3a1ff 100644
--- a/pkgs/development/python-modules/malduck/default.nix
+++ b/pkgs/development/python-modules/malduck/default.nix
@@ -9,6 +9,7 @@
   pefile,
   pycryptodomex,
   pyelftools,
+  pythonAtLeast,
   setuptools,
   pytestCheckHook,
   typing-extensions,
@@ -27,6 +28,11 @@ buildPythonPackage rec {
     hash = "sha256-Btx0HxiZWrb0TDpBokQGtBE2EDK0htONe/DwqlPgAd4=";
   };
 
+  patches = lib.optionals (pythonAtLeast "3.14") [
+    # python 3.14 ctypes rejects `_pack_` without `_layout_ = "ms"`.
+    ./python-3.14-ctypes-layout.patch
+  ];
+
   build-system = [ setuptools ];
 
   dependencies = [
diff --git a/pkgs/development/python-modules/malduck/python-3.14-ctypes-layout.patch b/pkgs/development/python-modules/malduck/python-3.14-ctypes-layout.patch
new file mode 100644
index 000000000000..738c3b4bc9da
--- /dev/null
+++ b/pkgs/development/python-modules/malduck/python-3.14-ctypes-layout.patch
@@ -0,0 +1,10 @@
+--- a/malduck/structure.py
++++ b/malduck/structure.py
+@@ -53,6 +53,7 @@
+             fields.append((field, type_))
+ 
+         class Klass(ctypes.Structure):
++            _layout_ = "ms"
+             _pack_ = self._pack_
+             _fields_ = fields
+