diff --git a/parson.c b/parson.c
index ca1652b..cca49d1 100644
--- a/parson.c
+++ b/parson.c
@@ -1,4 +1,6 @@
 /*
+ SPDX-License-Identifier: MIT
+
  Parson ( http://kgabis.github.com/parson/ )
  Copyright (c) 2012 - 2017 Krzysztof Gabis
 
diff --git a/parson.h b/parson.h
index 25cb00e..9374f7a 100644
--- a/parson.h
+++ b/parson.h
@@ -1,4 +1,6 @@
 /*
+ SPDX-License-Identifier: MIT
+
  Parson ( http://kgabis.github.com/parson/ )
  Copyright (c) 2012 - 2017 Krzysztof Gabis
 
diff --git a/tests.c b/tests.c
index ec9bfa2..6c79d07 100644
--- a/tests.c
+++ b/tests.c
@@ -1,4 +1,6 @@
 /*
+ SPDX-License-Identifier: MIT
+
  Parson ( http://kgabis.github.com/parson/ )
  Copyright (c) 2012 - 2017 Krzysztof Gabis