diff --git a/pkgs/development/python-modules/dpcontracts/default.nix b/pkgs/development/python-modules/dpcontracts/default.nix
new file mode 100644
index 000000000000..5a6491b7ee09
--- /dev/null
+++ b/pkgs/development/python-modules/dpcontracts/default.nix
@@ -0,0 +1,31 @@
+{ lib
+, buildPythonPackage
+, pythonOlder
+, fetchFromGitHub
+}:
+
+buildPythonPackage rec {
+  pname = "dpcontracts";
+  version = "unstable-2018-11-20";
+  format = "setuptools";
+  disabled = pythonOlder "3.5";
+
+  src = fetchFromGitHub {
+    owner = "deadpixi";
+    repo = "contracts";
+    rev = "45cb8542272c2ebe095c6efb97aa9407ddc8bf3c";
+    hash = "sha256-FygJPXo7lZ9tlfqY6KmPJ3PLIilMGLBr3013uj9hCEs=";
+  };
+
+  # package does not have any tests
+  doCheck = false;
+
+  pythonImportsCheck = [ "dpcontracts" ];
+
+  meta = with lib; {
+    description = "Provides a collection of decorators that makes it easy to write software using contracts";
+    homepage = "https://github.com/deadpixi/contracts";
+    license = licenses.lgpl3Only;
+    maintainers = with maintainers; [ gador ];
+  };
+}
diff --git a/pkgs/development/python-modules/icontract/default.nix b/pkgs/development/python-modules/icontract/default.nix
new file mode 100644
index 000000000000..7b7d20ce17f0
--- /dev/null
+++ b/pkgs/development/python-modules/icontract/default.nix
@@ -0,0 +1,78 @@
+{ lib
+, buildPythonPackage
+, pythonOlder
+, fetchFromGitHub
+, asttokens
+, typing-extensions
+, pytestCheckHook
+, yapf
+, docutils
+, pygments
+, dpcontracts
+, tabulate
+, py-cpuinfo
+, typeguard
+, astor
+, numpy
+, asyncstdlib
+}:
+
+buildPythonPackage rec {
+  pname = "icontract";
+  version = "2.6.1";
+  format = "setuptools";
+  disabled = pythonOlder "3.6";
+
+  src = fetchFromGitHub {
+    owner = "Parquery";
+    repo = pname;
+    rev = "refs/tags/v${version}";
+    hash = "sha256-QyuegyjVyRLQS0DjBJXpTDNeBM7LigGJ5cztVOO7e3Y=";
+  };
+
+  preCheck = ''
+    # we don't want to use the precommit.py script to build the package.
+    # For the tests to succeed, "ICONTRACT_SLOW" needs to be set.
+    # see https://github.com/Parquery/icontract/blob/aaeb1b06780a34b05743377e4cb2458780e808d3/precommit.py#L57
+    export ICONTRACT_SLOW=1
+  '';
+
+
+  propagatedBuildInputs = [
+    asttokens
+    typing-extensions
+  ];
+
+  checkInputs = [
+    pytestCheckHook
+    yapf
+    docutils
+    pygments
+    dpcontracts
+    tabulate
+    py-cpuinfo
+    typeguard
+    astor
+    numpy
+    asyncstdlib
+  ];
+
+  disabledTestPaths = [
+    # needs an old version of deal to comply with the tests
+    # see https://github.com/Parquery/icontract/issues/244
+    "tests_with_others/test_deal.py"
+    # mypy decorator checks don't pass. For some reaseon mypy
+    # doesn't check the python file provided in the test.
+    "tests/test_mypy_decorators.py"
+  ];
+
+  pythonImportsCheck = [ "icontract" ];
+
+  meta = with lib; {
+    description = "Provide design-by-contract with informative violation messages";
+    homepage = "https://github.com/Parquery/icontract";
+    changelog = "https://github.com/Parquery/icontract/blob/master/CHANGELOG.rst";
+    license = licenses.mit;
+    maintainers = with maintainers; [ gador ];
+  };
+}
diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index 693b3e0101d2..c4c53ddcb76e 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -2544,6 +2544,8 @@ in {
 
   dpath = callPackage ../development/python-modules/dpath { };
 
+  dpcontracts = callPackage ../development/python-modules/dpcontracts { };
+
   dpkt = callPackage ../development/python-modules/dpkt { };
 
   dragonfly = callPackage ../development/python-modules/dragonfly { };
@@ -4103,6 +4105,8 @@ in {
 
   idasen = callPackage ../development/python-modules/idasen { };
 
+  icontract = callPackage ../development/python-modules/icontract { };
+
   identify = callPackage ../development/python-modules/identify { };
 
   idna = callPackage ../development/python-modules/idna { };