diff --git a/README.md b/README.md
index 03b98e683d9e1ea42b02938af9a88bd2c61ea603..02521c194d168dd3fe63f73dd6adafdca4a44b77 100644
--- a/README.md
+++ b/README.md
@@ -61,8 +61,9 @@ and need to add or change some public method, feel free to suggest it!
 
 ## License
 
-The ModemManager and mmcli binaries are both GPLv2+.
-The libmm-glib library is LGPLv2+.
+The ModemManager and mmcli binaries are both GPLv2+ (See COPYING).
+The libmm-glib library and the ModemManager API headers are LGPLv2+ (See
+COPYING.LIB).
 
 ## Code of Conduct
 
diff --git a/include/ModemManager-compat.h b/include/ModemManager-compat.h
index 048ac7d9e0af6e7a7597bbb3e154faf29fd4af53..3d861dad932cdde49ddc84ef0b563064eee665a6 100644
--- a/include/ModemManager-compat.h
+++ b/include/ModemManager-compat.h
@@ -1,14 +1,21 @@
 /* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
 /*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
+ * ModemManager Interface Specification
  *
- * This program is distributed in the hope that it will be useful,
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details:
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA.
  *
  * Copyright (C) 2017 Google, Inc.
  */
diff --git a/include/ModemManager-enums.h b/include/ModemManager-enums.h
index 3cd46381be5a9e20d5def54051c415fea1cfcf80..a12e1a244b25750ae423c49efa2686234c36f1c2 100644
--- a/include/ModemManager-enums.h
+++ b/include/ModemManager-enums.h
@@ -1,14 +1,21 @@
 /* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
 /*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
+ * ModemManager Interface Specification
  *
- * This program is distributed in the hope that it will be useful,
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details:
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA.
  *
  * Copyright (C) 2011 Red Hat, Inc.
  * Copyright (C) 2011 Google, Inc.
diff --git a/include/ModemManager-errors.h b/include/ModemManager-errors.h
index 4a7c5ce7d40958bd369b59101e73592c4bea890f..572b8a007ce7c8edc07719c027d276ea9ac47f16 100644
--- a/include/ModemManager-errors.h
+++ b/include/ModemManager-errors.h
@@ -1,14 +1,21 @@
 /* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
 /*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
+ * ModemManager Interface Specification
  *
- * This program is distributed in the hope that it will be useful,
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details:
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA.
  *
  * Copyright (C) 2011 Red Hat, Inc.
  * Copyright (C) 2011 Google, Inc.
diff --git a/include/ModemManager-tags.h b/include/ModemManager-tags.h
index 74e9a0d7b0f9cd4a4dc15470253a515411d9128d..fc2136aec40085ddc34f726235303a6bc375b84b 100644
--- a/include/ModemManager-tags.h
+++ b/include/ModemManager-tags.h
@@ -1,14 +1,21 @@
 /* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
 /*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
+ * ModemManager Interface Specification
  *
- * This program is distributed in the hope that it will be useful,
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details:
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA.
  *
  * Copyright (C) 2018 Aleksander Morgado <aleksander@aleksander.es>
  */
diff --git a/include/ModemManager-version.h.in b/include/ModemManager-version.h.in
index b3b20003b4e865f7efaf0179f7ccb83cdf6b7a0c..308f1511fec519550a5b94b5156cfa651b94e2dd 100644
--- a/include/ModemManager-version.h.in
+++ b/include/ModemManager-version.h.in
@@ -1,5 +1,7 @@
 /* -*- Mode: C; tab-width: 4; indent-tabs-mode: t; c-basic-offset: 4 -*- */
 /*
+ * ModemManager Interface Specification
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
diff --git a/include/ModemManager.h b/include/ModemManager.h
index 530bd210304378b3c987972f025218a7263f9934..02bd879e02fc0f8ff4c3cae4e550eeb04888084e 100644
--- a/include/ModemManager.h
+++ b/include/ModemManager.h
@@ -1,6 +1,5 @@
 /*
  * ModemManager Interface Specification
- * version 1.x
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public