diff --git a/test/calibration/test_setup_library.py b/test/calibration/test_setup_library.py
index 1c1307c97a..12900dbf38 100644
--- a/test/calibration/test_setup_library.py
+++ b/test/calibration/test_setup_library.py
@@ -25,7 +25,7 @@
 from qiskit_experiments.framework.json import ExperimentEncoder, ExperimentDecoder
 
 
-class TestLibrary(FixedFrequencyTransmon):
+class MutableTestLibrary(FixedFrequencyTransmon):
     """A subclass designed for test_hash_warn.
 
     This class ensures that FixedFrequencyTransmon is preserved if anything goes wrong
@@ -197,26 +197,27 @@ def test_hash_warn(self):
         4. A warning is raised since the class definition has changed.
         """
 
-        lib1 = TestLibrary()
+        lib1 = MutableTestLibrary()
         lib_data = json.dumps(lib1, cls=ExperimentEncoder)
         lib2 = json.loads(lib_data, cls=ExperimentDecoder)
 
         self.assertTrue(self._test_library_equivalence(lib1, lib2))
 
         # stash method build schedules to avoid other tests from failing
-        build_schedules = TestLibrary._build_schedules
+        build_schedules = MutableTestLibrary._build_schedules
 
         def _my_build_schedules():
             """A dummy function to change the class behaviour."""
             pass
 
         # Change the schedule behaviour
-        TestLibrary._build_schedules = _my_build_schedules
+        MutableTestLibrary._build_schedules = _my_build_schedules
 
         with self.assertWarns(UserWarning):
-            json.loads(lib_data, cls=ExperimentDecoder)
-
-        TestLibrary._build_schedules = build_schedules
+            try:
+                json.loads(lib_data, cls=ExperimentDecoder)
+            finally:
+                MutableTestLibrary._build_schedules = build_schedules
 
     def _test_library_equivalence(self, lib1, lib2) -> bool:
         """Test if libraries are equivalent.