diff --git a/inema/frank.py b/inema/frank.py
index cb448db..1f07665 100755
--- a/inema/frank.py
+++ b/inema/frank.py
@@ -1,6 +1,7 @@
 #!/usr/bin/env python3
 
 # 2016, Georg Sauthoff <mail@georg.so>, LGPLv3+
+# SPDX-Identifier: LGPL-3.0-or-later
 
 import argparse
 import configparser
diff --git a/inema/inema.py b/inema/inema.py
index e3d5527..2f21179 100644
--- a/inema/inema.py
+++ b/inema/inema.py
@@ -1,5 +1,6 @@
 #!/usr/bin/python
 # -*- coding: utf-8 -*-
+# SPDX-Identifier: LGPL-3.0-or-later
 
 from datetime import date
 import json
diff --git a/inema/utils.py b/inema/utils.py
index e932e67..87396bc 100644
--- a/inema/utils.py
+++ b/inema/utils.py
@@ -1,3 +1,4 @@
+# SPDX-Identifier: LGPL-3.0-or-later
 
 import hashlib
 from datetime import datetime
diff --git a/inema/wpint.py b/inema/wpint.py
index 01455c3..3442ed0 100644
--- a/inema/wpint.py
+++ b/inema/wpint.py
@@ -9,6 +9,8 @@
 # completely different API with different standards (REST vs. SOAP) with
 # literally nothing in common to the old Internetmarke API
 
+# SPDX-Identifier: LGPL-3.0-or-later
+
 import json
 import logging