diff --git a/pkgs/development/python-modules/gym/default.nix b/pkgs/development/python-modules/gym/default.nix
index d826fc33324..263bdfa2f47 100644
--- a/pkgs/development/python-modules/gym/default.nix
+++ b/pkgs/development/python-modules/gym/default.nix
@@ -12,13 +12,6 @@ buildPythonPackage rec {
     sha256 = "96a7dd4e9cdb39e30c7a79e5773570fd9408f7fdb58c714c293cfbb314818eb6";
   };
 
-  postPatch = ''
-    substituteInPlace setup.py \
-      --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
   ];