diff --git a/pkgs/development/python-modules/pygls/default.nix b/pkgs/development/python-modules/pygls/default.nix
index 5560e855d87f..7ca6b344c9a2 100644
--- a/pkgs/development/python-modules/pygls/default.nix
+++ b/pkgs/development/python-modules/pygls/default.nix
@@ -1,4 +1,5 @@
 { lib
+, stdenv
 , buildPythonPackage
 , pythonOlder
 , fetchFromGitHub
@@ -45,6 +46,11 @@ buildPythonPackage rec {
   # Fixes hanging tests on Darwin
   __darwinAllowLocalNetworking = true;
 
+  preCheck = lib.optionalString stdenv.isDarwin ''
+    # Darwin issue: OSError: [Errno 24] Too many open files
+    ulimit -n 1024
+  '';
+
   pythonImportsCheck = [ "pygls" ];
 
   meta = with lib; {