diff --git a/poky/bitbake/lib/prserv/__init__.py b/poky/bitbake/lib/prserv/__init__.py
index c3cb73a..9961040 100644
--- a/poky/bitbake/lib/prserv/__init__.py
+++ b/poky/bitbake/lib/prserv/__init__.py
@@ -1,3 +1,7 @@
+#
+# SPDX-License-Identifier: GPL-2.0-only
+#
+
 __version__ = "1.0.0"
 
 import os, time
diff --git a/poky/bitbake/lib/prserv/db.py b/poky/bitbake/lib/prserv/db.py
index 495d09f..d6188a6 100644
--- a/poky/bitbake/lib/prserv/db.py
+++ b/poky/bitbake/lib/prserv/db.py
@@ -1,3 +1,7 @@
+#
+# SPDX-License-Identifier: GPL-2.0-only
+#
+
 import logging
 import os.path
 import errno
diff --git a/poky/bitbake/lib/prserv/serv.py b/poky/bitbake/lib/prserv/serv.py
index 6a99728..be3acec 100644
--- a/poky/bitbake/lib/prserv/serv.py
+++ b/poky/bitbake/lib/prserv/serv.py
@@ -1,3 +1,7 @@
+#
+# SPDX-License-Identifier: GPL-2.0-only
+#
+
 import os,sys,logging
 import signal, time
 from xmlrpc.server import SimpleXMLRPCServer, SimpleXMLRPCRequestHandler