diff --git a/tests/test_imports.py b/tests/test_imports.py
index 7e5914c..683e724 100644
--- a/tests/test_imports.py
+++ b/tests/test_imports.py
@@ -23,6 +23,8 @@ def test_all_submodules_import():
         )
     ]
 
+    assert module_names, "walk_packages found no submodules - check smileyface.__path__"
+
     for name in module_names:
         try:
             importlib.import_module(name)