diff --git a/pkgs/development/python-modules/ndg-httpsclient/default.nix b/pkgs/development/python-modules/ndg-httpsclient/default.nix
index 0082b8e8db23..39429950b71c 100644
--- a/pkgs/development/python-modules/ndg-httpsclient/default.nix
+++ b/pkgs/development/python-modules/ndg-httpsclient/default.nix
@@ -1,6 +1,7 @@
 { lib
 , buildPythonPackage
 , fetchFromGitHub
+, pyasn1
 , pyopenssl
 }:
 
@@ -8,8 +9,6 @@ buildPythonPackage rec {
   version = "0.5.1";
   pname = "ndg-httpsclient";
 
-  propagatedBuildInputs = [ pyopenssl ];
-
   src = fetchFromGitHub {
     owner = "cedadev";
     repo = "ndg_httpsclient";
@@ -17,6 +16,12 @@ buildPythonPackage rec {
     sha256 = "0lhsgs4am4xyjssng5p0vkfwqncczj1dpa0vss4lrhzq86mnn5rz";
   };
 
+
+  propagatedBuildInputs = [
+    pyasn1
+    pyopenssl
+  ];
+
   # uses networking
   doCheck = false;