diff --git a/src/dependency_injector/providers.pyx b/src/dependency_injector/providers.pyx
index d276903b..12d7ad0f 100644
--- a/src/dependency_injector/providers.pyx
+++ b/src/dependency_injector/providers.pyx
@@ -5036,7 +5036,7 @@ def _resolve_calling_module():
 
 def _resolve_calling_package_name():
     module = _resolve_calling_module()
-    return module.__package__
+    return getattr(module, "__package__", None)
 
 
 cpdef _copy_parent(object from_, object to, dict memo):