diff --git a/pkgs/development/python-modules/grpcio/default.nix b/pkgs/development/python-modules/grpcio/default.nix
index 9311838627a..55d569c9054 100644
--- a/pkgs/development/python-modules/grpcio/default.nix
+++ b/pkgs/development/python-modules/grpcio/default.nix
@@ -6,6 +6,8 @@ buildPythonPackage rec {
   inherit (grpc) src version;
   pname = "grpcio";
 
+  outputs = [ "out" "dev" ];
+
   nativeBuildInputs = [ cython pkgconfig ]
                     ++ stdenv.lib.optional stdenv.isDarwin darwin.cctools;