diff --git a/pkgs/development/python-modules/gym/default.nix b/pkgs/development/python-modules/gym/default.nix
index 7588135e33c3..482b2c64aae2 100644
--- a/pkgs/development/python-modules/gym/default.nix
+++ b/pkgs/development/python-modules/gym/default.nix
@@ -14,8 +14,10 @@ buildPythonPackage rec {
 
   postPatch = ''
     substituteInPlace setup.py \
-      --replace "pyglet>=1.2.0,<=1.3.2" "pyglet"
+      --replace "pyglet>=1.2.0,<=1.3.2" "pyglet" \
+      --replace "cloudpickle>=1.2.0,<1.4.0" "cloudpickle~=1.2"
   '';
+  # cloudpickle range has been expanded in package but not yet released
 
   propagatedBuildInputs = [
     numpy requests six pyglet scipy cloudpickle
@@ -24,6 +26,8 @@ buildPythonPackage rec {
   # The test needs MuJoCo that is not free library.
   doCheck = false;
 
+  pythonImportCheck = [ "gym" ];
+
   meta = with lib; {
     description = "A toolkit by OpenAI for developing and comparing your reinforcement learning agents";
     homepage = "https://gym.openai.com/";