diff --git a/core/tests/test_unittest.py b/core/tests/test_unittest.py
new file mode 100644
index 000000000..63c657d6d
--- /dev/null
+++ b/core/tests/test_unittest.py
@@ -0,0 +1,13 @@
+from common import *
+
+
+class TestUnittest(unittest.TestCase):
+
+    def test_debug(self):
+        if not __debug__:
+            # Fail the test if debug is turned off, because `assert` is not executed then.
+            self.assertTrue(False)
+
+
+if __name__ == "__main__":
+    unittest.main()