diff --git a/pkgs/development/python-modules/watchfiles/default.nix b/pkgs/development/python-modules/watchfiles/default.nix
index b644571b9e3f..3f75354376dd 100644
--- a/pkgs/development/python-modules/watchfiles/default.nix
+++ b/pkgs/development/python-modules/watchfiles/default.nix
@@ -53,6 +53,11 @@ buildPythonPackage rec {
     anyio
   ];
 
+  # Tests need these permissions in order to use the FSEvents API on macOS.
+  sandboxProfile = ''
+    (allow mach-lookup (global-name "com.apple.FSEvents"))
+  '';
+
   nativeCheckInputs = [
     dirty-equals
     pytest-mock