diff --git a/pkgs/development/python-modules/pynacl/default.nix b/pkgs/development/python-modules/pynacl/default.nix
index f8696dd54ac0..8c5c239aeb41 100644
--- a/pkgs/development/python-modules/pynacl/default.nix
+++ b/pkgs/development/python-modules/pynacl/default.nix
@@ -6,6 +6,7 @@
 , libsodium
 , cffi
 , hypothesis
+, six
 }:
 
 buildPythonPackage rec {
@@ -23,10 +24,14 @@ buildPythonPackage rec {
     libsodium
   ];
 
-  propagatedBuildInputs = [
+  propagatedNativeBuildInputs = [
     cffi
   ];
 
+  propagatedBuildInputs = [
+    six
+  ];
+
   checkInputs = [
     hypothesis
     pytestCheckHook