diff --git a/okdmr/.gitignore b/okdmr/.gitignore
index 5a59066..1605422 100644
--- a/okdmr/.gitignore
+++ b/okdmr/.gitignore
@@ -1,2 +1,2 @@
 # okdmr should not be package, but namespace
-__init__.py
\ No newline at end of file
+/okdmr/__init__.py
\ No newline at end of file
diff --git a/okdmr/dmrlib/storage/__init__.py b/okdmr/dmrlib/storage/__init__.py
new file mode 100644
index 0000000..1f82112
--- /dev/null
+++ b/okdmr/dmrlib/storage/__init__.py
@@ -0,0 +1,4 @@
+from typing import Tuple
+
+ADDRESS_TYPE = Tuple[str, int]
+ADDRESS_EMPTY: ADDRESS_TYPE = ("", 0)
diff --git a/okdmr/tests/dmrlib/storage/__init__.py b/okdmr/tests/dmrlib/storage/__init__.py
new file mode 100644
index 0000000..e69de29