diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,3 +1,7 @@
+### 3.0.26
+
++ Make sure that the @data@ argument of [CellLayoutDataFunc](https://hackage.haskell.org/package/gi-gtk/docs/GI-Gtk-Callbacks.html#t:CellLayoutDataFunc) is properly anotated as a closure argument.
+
 ### 3.0.25
 
 + Update stack version to 12.10
diff --git a/Gtk.overrides b/Gtk.overrides
--- a/Gtk.overrides
+++ b/Gtk.overrides
@@ -18,6 +18,9 @@
 # https://github.com/haskell-gi/haskell-gi/issues/104
 set-attr Gtk/Builder/add_callback_symbol/@parameters/callback_symbol scope notified
 
+# Not properly annotated in older versions of gtk
+set-attr Gtk/CellLayoutDataFunc/@parameters/data closure 4
+
 # Missing nullable return annotation, see
 # https://github.com/haskell-gi/haskell-gi/issues/192
 set-attr Gtk/TreePath/get_indices_with_depth/@return-value nullable 1
diff --git a/LICENSE b/LICENSE
--- a/LICENSE
+++ b/LICENSE
@@ -1,3 +1,17 @@
+The gi-gtk library and included works are provided under the terms of the
+GNU Library General Public License (LGPL) version 2.1 with the following
+exception:
+
+Static linking of applications or any other source to the gi-gtk library
+does not constitute a modified or derivative work and does not require
+the author(s) to provide source code for said work, to link against the
+shared gi-gtk libraries, or to link their applications against a
+user-supplied version of gi-gtk. If you link applications to a modified
+version of gi-gtk, then the changes to gi-gtk must be provided under the
+terms of the LGPL.
+
+----------------------------------------------------------------------------
+
                   GNU LESSER GENERAL PUBLIC LICENSE
                        Version 2.1, February 1999
 
diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # Documentation
 Autogenerated documentation for this package can be found at
 
-[https://hackage.haskell.org/package/gi-gtk-3.0.25/docs/GI-Gtk.html](https://hackage.haskell.org/package/gi-gtk-3.0.25/docs/GI-Gtk.html)
+[https://hackage.haskell.org/package/gi-gtk-3.0.26/docs/GI-Gtk.html](https://hackage.haskell.org/package/gi-gtk-3.0.26/docs/GI-Gtk.html)
 
 For general documentation on using [haskell-gi](https://github.com/haskell-gi/haskell-gi) based bindings, see [the project page](https://github.com/haskell-gi/haskell-gi) or [the Wiki](https://github.com/haskell-gi/haskell-gi/wiki).
diff --git a/gi-gtk.cabal b/gi-gtk.cabal
--- a/gi-gtk.cabal
+++ b/gi-gtk.cabal
@@ -1,5 +1,5 @@
 name:                 gi-gtk
-version:              3.0.25
+version:              3.0.26
 synopsis:             Gtk bindings
 description:          Bindings for Gtk, autogenerated by haskell-gi.
 homepage:             https://github.com/haskell-gi/haskell-gi