diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,3 +1,8 @@
+### 2.0.35
+
++ Make sure that the `data` argument of `AsyncReadyCallback` is marked
+  as a `user_data` type argument. See [issue 405](https://github.com/haskell-gi/haskell-gi/issues/405).
+
 ### 2.0.34
 
 + Expose `InputStreamClass` and `SeekableIface`, see [issue 441](https://github.com/haskell-gi/haskell-gi/issues/441).
diff --git a/Gio.overrides b/Gio.overrides
--- a/Gio.overrides
+++ b/Gio.overrides
@@ -10,6 +10,9 @@
 ignore io_modules_load_all_in_directory
 ignore io_modules_load_all_in_directory_with_scope
 
+# This is a user_data type argument, but it is not marked as such.
+set-attr Gio/AsyncReadyCallback/@parameters/data closure 2
+
 # Properly marked as filename in recent Gio versions.
 set-attr Gio/AppInfo/get_executable/@return-value/@type name filename
 
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-gio-2.0.34/docs/GI-Gio.html](https://hackage.haskell.org/package/gi-gio-2.0.34/docs/GI-Gio.html)
+[https://hackage.haskell.org/package/gi-gio-2.0.35/docs/GI-Gio.html](https://hackage.haskell.org/package/gi-gio-2.0.35/docs/GI-Gio.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/Setup.hs b/Setup.hs
--- a/Setup.hs
+++ b/Setup.hs
@@ -11,7 +11,7 @@
   where name = "Gio"
         version = "2.0"
         pkgName = "gi-gio"
-        pkgVersion = "2.0.34"
+        pkgVersion = "2.0.35"
         overridesFile = Just "Gio.overrides"
         verbose = False
         outputDir = Nothing
diff --git a/gi-gio.cabal b/gi-gio.cabal
--- a/gi-gio.cabal
+++ b/gi-gio.cabal
@@ -1,5 +1,5 @@
 name:                 gi-gio
-version:              2.0.34
+version:              2.0.35
 synopsis:             Gio bindings
 description:          Bindings for Gio, autogenerated by haskell-gi.
 homepage:             https://github.com/haskell-gi/haskell-gi