diff --git a/Lib/test/test__xxsubinterpreters.py b/Lib/test/test__xxsubinterpreters.py
index 207b5db..30f8f98 100644
--- a/Lib/test/test__xxsubinterpreters.py
+++ b/Lib/test/test__xxsubinterpreters.py
@@ -759,7 +759,11 @@
         main, = interpreters.list_all()
         interp = interpreters.create()
         with _running(interp):
-            with self.assertRaises(RuntimeError):
+            self.assertTrue(interpreters.is_running(interp),
+                            msg=f"Interp {interp} should be running before destruction.")
+
+            with self.assertRaises(RuntimeError,
+                                   msg=f"Should not be able to destroy interp {interp} while it's still running."):
                 interpreters.destroy(interp)
             self.assertTrue(interpreters.is_running(interp))