diff --git a/pkgs/by-name/py/pychess/package.nix b/pkgs/by-name/py/pychess/package.nix
index ea52b105a179..3b7cd8afd4fd 100644
--- a/pkgs/by-name/py/pychess/package.nix
+++ b/pkgs/by-name/py/pychess/package.nix
@@ -44,6 +44,7 @@ python3Packages.buildPythonApplication rec {
     sqlalchemy
     pexpect
     psutil
+    standard-telnetlib
     websockets
     ptyprocess
   ];