diff --git a/pkgs/development/python-modules/skyfield/default.nix b/pkgs/development/python-modules/skyfield/default.nix
index 73e6ea9ed041..f56a7c8aad56 100644
--- a/pkgs/development/python-modules/skyfield/default.nix
+++ b/pkgs/development/python-modules/skyfield/default.nix
@@ -1,4 +1,4 @@
-{ lib, buildPythonPackage, fetchFromGitHub, certifi, numpy, sgp4, jplephem
+{ lib, buildPythonPackage, pythonOlder, fetchFromGitHub, certifi, numpy, sgp4, jplephem
 , pandas, ipython, matplotlib, assay
 }:
 
@@ -17,6 +17,10 @@ buildPythonPackage rec {
 
   nativeCheckInputs = [ pandas ipython matplotlib assay ];
 
+  # assay is broken on Python >= 3.11
+  # https://github.com/brandon-rhodes/assay/issues/15
+  doCheck = pythonOlder "3.11";
+
   checkPhase = ''
     runHook preCheck