diff --git a/src/calibre/utils/run_tests.py b/src/calibre/utils/run_tests.py
index fc25d557e7..7a6669ae27 100644
--- a/src/calibre/utils/run_tests.py
+++ b/src/calibre/utils/run_tests.py
@@ -330,9 +330,13 @@ def run_test(test_name, verbosity=4, buffer=False):
 
 def run_cli(suite, verbosity=4, buffer=True):
     r = unittest.TextTestRunner
-    # r.resultclass = unittest.TextTestResult if verbosity < 2 else TestResult
+    r.resultclass = unittest.TextTestResult if verbosity < 2 else TestResult
     init_env()
     result = r(verbosity=verbosity, buffer=buffer and not is_ci).run(suite)
-    print(111111111, result, flush=True)
     rc = 0 if result.wasSuccessful() else 1
-    os._exit(rc)
+    if is_ci:
+        # for some reason interpreter shutdown hangs probably some non-daemonic
+        # thread
+        os._exit(rc)
+    else:
+        raise SystemExit(rc)