diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,3 +1,13 @@
+### 3.0.15
+
++ Fix introspection info for [uIManagerGetAction](https://hackage.haskell.org/package/gi-gtk/docs/GI-Gtk-Objects-UIManager.html#v:uIManagerGetAction), [uIManagerGetWidget](https://hackage.haskell.org/package/gi-gtk/docs/GI-Gtk-Objects-UIManager.html#v:uIManagerGetWidget), [actionGroupGetAction](https://hackage.haskell.org/package/gi-gtk/docs/GI-Gtk-Objects-ActionGroup.html#v:actionGroupGetAction), [textMarkGetName](https://hackage.haskell.org/package/gi-gtk/docs/GI-Gtk-Objects-TextMark.html#v:textMarkGetName) and [notebookGetTabLabel](https://hackage.haskell.org/package/gi-gtk/docs/GI-Gtk-Objects-Notebook.html#v:notebookGetTabLabel). In all these cases the function can return NULL, but it was not marked as such in the introspection data.
+
++ Fix introspection data for [builderAddCallbackSymbol](https://hackage.haskell.org/package/gi-gtk/docs/GI-Gtk-Objects-Builder.html#v:builderAddCallbackSymbol). The `callbackSymbol` argument was marked as `(scope async)`, which meant that it was safe to free after the first invokation, but this was not correct, and leads to [crashes](https://github.com/haskell-gi/haskell-gi/issues/104).
+
+### 3.0.14
+
+Update lower version bound on haskell-gi (>= 0.20.1).
+
 ### 3.0.13
 
 Update nullable overrides to match gtk+ 3.22.11.
diff --git a/Gtk.overrides b/Gtk.overrides
--- a/Gtk.overrides
+++ b/Gtk.overrides
@@ -13,6 +13,11 @@
 # upstream issue: https://bugzilla.gnome.org/show_bug.cgi?id=761339
 ignore WidgetPath.iter_add_qclass
 
+# Wrong introspection annotation, leading to crashes. See
+# https://bugzilla.gnome.org/show_bug.cgi?id=783381
+# https://github.com/haskell-gi/haskell-gi/issues/104
+set-attr Gtk/Builder/add_callback_symbol/@parameters/callback_symbol scope notified
+
 # Wrong introspection annotation, see
 # https://bugzilla.gnome.org/show_bug.cgi?id=693393
 set-attr Gtk/PrintOperation/create-custom-widget/@return-value transfer-ownership full
@@ -26,6 +31,16 @@
 # https://bugzilla.gnome.org/show_bug.cgi?id=674537
 set-attr Gtk/MenuPositionFunc/@parameters/x direction inout
 set-attr Gtk/MenuPositionFunc/@parameters/y direction inout
+
+# Missing nullable annotations in the return values, see
+# https://github.com/haskell-gi/haskell-gi/issues/95
+# https://bugzilla.gnome.org/show_bug.cgi?id=781935
+# https://bugzilla.gnome.org/show_bug.cgi?id=781936
+set-attr Gtk/UIManager/get_widget/@return-value nullable 1
+set-attr Gtk/UIManager/get_action/@return-value nullable 1
+set-attr Gtk/ActionGroup/get_action/@return-value nullable 1
+set-attr Gtk/TextMark/get_name/@return-value nullable 1
+set-attr Gtk/Notebook/get_tab_label/@return-value nullable 1
 
 if osx
     # Not supported in Quartz version of Gtk
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-3.0.14/docs/GI-Gtk.html](https://hackage.haskell.org/package/gi-gtk-3.0.14/docs/GI-Gtk.html)
+[https://hackage.haskell.org/package/gi-gtk-3.0.15/docs/GI-Gtk.html](https://hackage.haskell.org/package/gi-gtk-3.0.15/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:              3.0.14
+version:              3.0.15
 synopsis:             Gtk bindings
 description:          Bindings for Gtk, autogenerated by haskell-gi.
 homepage:             https://github.com/haskell-gi/haskell-gi