diff --git a/pkgs/development/python-modules/gym/default.nix b/pkgs/development/python-modules/gym/default.nix
index 5bcfb64a184d..5c3fed0db26b 100644
--- a/pkgs/development/python-modules/gym/default.nix
+++ b/pkgs/development/python-modules/gym/default.nix
@@ -7,13 +7,13 @@
 
 buildPythonPackage rec {
   pname = "gym";
-  version = "0.19.0";
+  version = "0.21.0";
 
   src = fetchFromGitHub {
     owner = "openai";
     repo = pname;
     rev = version;
-    sha256 = "sha256-0O/s9OVNGQmeX9j8B1x63RxdI6dhqfTEJcgDH2jtCv4=";
+    sha256 = "12b545xz0r2g4z5r7f8amxl7nm0lqymkzwcwhg1bni9h0sxwpv6c";
   };
 
   propagatedBuildInputs = [