diff --git a/pkgs/development/python-modules/nix-kernel/default.nix b/pkgs/development/python-modules/nix-kernel/default.nix
index 5c4b270d2e7a..a14a12b5b4f0 100644
--- a/pkgs/development/python-modules/nix-kernel/default.nix
+++ b/pkgs/development/python-modules/nix-kernel/default.nix
@@ -2,6 +2,7 @@
   lib,
   buildPythonPackage,
   fetchFromGitHub,
+  setuptools,
   isPy3k,
   pexpect,
   notebook,
@@ -11,7 +12,7 @@
 buildPythonPackage rec {
   pname = "nix-kernel";
   version = "unstable-2020-04-26";
-  format = "setuptools";
+  pyproject = true;
 
   disabled = !isPy3k;
 
@@ -24,14 +25,16 @@ buildPythonPackage rec {
 
   postPatch = ''
     substituteInPlace nix-kernel/kernel.py \
-      --replace "'nix'" "'${nix}/bin/nix'" \
-      --replace "'nix repl'" "'${nix}/bin/nix repl'"
+      --replace-fail "'nix'" "'${nix}/bin/nix'" \
+      --replace-fail "'nix repl'" "'${nix}/bin/nix repl'"
 
     substituteInPlace setup.py \
-      --replace "cmdclass={'install': install_with_kernelspec}," ""
+      --replace-fail "cmdclass={'install': install_with_kernelspec}," ""
   '';
 
-  propagatedBuildInputs = [
+  build-system = [ setuptools ];
+
+  dependencies = [
     pexpect
     notebook
   ];