diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..65b2eeb
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,4 @@
+
+# x.x.x
+
+First version
diff --git a/README.md b/README.md
index be6680a..b07face 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,7 @@
 # Optifik
 
+TODO: write a paragraph here...
+
 
 This library replaces oospectro.
 
@@ -48,3 +50,7 @@ cd docs
 make html
 ```
 
+## Licence
+
+The source code is released under the GNU General Public License v3.0.
+See LICENSE for details.
diff --git a/pyproject.toml b/pyproject.toml
index d05cb02..e53c231 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -6,7 +6,7 @@ authors = [
   { name = "François Boulogne", email = "francois.boulogne@cnrs.fr" },
   { name = "Victor Ziapkoff", email = "victor.ziapkoff@universite-paris-saclay.fr" },
 ]
-license = "GPL-3.0-or-later"
+license = "GPL-3.0"
 readme = "README.md"
 requires-python = ">=3.13"
 dependencies = [