diff --git a/pkgs/development/python-modules/poetry-core/default.nix b/pkgs/development/python-modules/poetry-core/default.nix
index daf45528202f..270c78a69826 100644
--- a/pkgs/development/python-modules/poetry-core/default.nix
+++ b/pkgs/development/python-modules/poetry-core/default.nix
@@ -11,7 +11,6 @@
 , pytest-mock
 , pytestCheckHook
 , setuptools
-, tomlkit
 , virtualenv
 }:
 
@@ -54,7 +53,6 @@ buildPythonPackage rec {
     pytest-mock
     pytestCheckHook
     setuptools
-    tomlkit
     virtualenv
   ];
 
diff --git a/pkgs/development/python-modules/tomlkit/default.nix b/pkgs/development/python-modules/tomlkit/default.nix
index 861560c2aee0..1d1fb1e4b684 100644
--- a/pkgs/development/python-modules/tomlkit/default.nix
+++ b/pkgs/development/python-modules/tomlkit/default.nix
@@ -6,17 +6,21 @@
 , functools32, typing ? null
 , pytestCheckHook
 , pyaml
+, poetry-core
 }:
 
 buildPythonPackage rec {
   pname = "tomlkit";
   version = "0.11.6";
+  format = "pyproject";
 
   src = fetchPypi {
     inherit pname version;
     hash = "sha256-cblS5XIWiJN/sCz501TbzweFBmFJ0oVeRFMevdK2XXM=";
   };
 
+  nativeBuildInputs = [ poetry-core ];
+
   propagatedBuildInputs =
     lib.optionals isPy27 [ enum34 functools32 ]
     ++ lib.optional isPy27 typing;