diff --git a/src/sdf/module.mk b/src/sdf/module.mk
index 978e13f13..141e05f4f 100644
--- a/src/sdf/module.mk
+++ b/src/sdf/module.mk
@@ -1,3 +1,16 @@
+#
+# FreeType 2 Signed Distance Field module definition
+#
+
+
+# Copyright (C) 2020 by
+# David Turner, Robert Wilhelm, and Werner Lemberg.
+#
+# This file is part of the FreeType project, and may only be used, modified,
+# and distributed under the terms of the FreeType project license,
+# LICENSE.TXT.  By continuing to use, modify, or distribute this file you
+# indicate that you have read the license and understand and accept it
+# fully.
 
 
 FTMODULE_H_COMMANDS += SDF_RENDERER
diff --git a/src/sdf/rules.mk b/src/sdf/rules.mk
index a410d733c..361ae6d9e 100644
--- a/src/sdf/rules.mk
+++ b/src/sdf/rules.mk
@@ -1,3 +1,16 @@
+#
+# FreeType 2 Signed Distance Field driver configuration rules
+#
+
+
+# Copyright (C) 2020 by
+# David Turner, Robert Wilhelm, and Werner Lemberg.
+#
+# This file is part of the FreeType project, and may only be used, modified,
+# and distributed under the terms of the FreeType project license,
+# LICENSE.TXT.  By continuing to use, modify, or distribute this file you
+# indicate that you have read the license and understand and accept it
+# fully.
 
 
 # sdf driver directory