diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,3 +1,7 @@
+### 3.0.20
+
++ Make the 'events' parameter to ['widgetAddEvents'](https://hackage.haskell.org/package/gi-gtk/docs/GI-Gtk-Objects-Widget.html#v:widgetAddEvents) and ['widgetSetEvents](https://hackage.haskell.org/package/gi-gtk/docs/GI-Gtk-Objects-Widget.html#v:widgetSetEvents) a [GdkEventMask](https://hackage.haskell.org/package/gi-gdk/docs/GI-Gdk-Flags.html#t:EventMask), see [issue 136](https://github.com/haskell-gi/haskell-gi/issues/136).
+
 ### 3.0.19
 
 + Remove enable-overloading flags, and use instead explicit CPP checks for 'haskell-gi-overloading-1.0', see [how to disable overloading](https://github.com/haskell-gi/haskell-gi/wiki/Overloading\#disabling-overloading).
diff --git a/Gtk.overrides b/Gtk.overrides
--- a/Gtk.overrides
+++ b/Gtk.overrides
@@ -47,6 +47,13 @@
 # https://github.com/haskell-gi/haskell-gi/issues/111
 set-attr Gtk/Bin/get_child/@return-value nullable 1
 
+# Marked as gint, but really GdkEventMask.
+# https://github.com/haskell-gi/haskell-gi/issues/136
+set-attr Gtk/Widget/add_events/@parameters/events/@type name Gdk.EventMask
+set-attr Gtk/Widget/add_events/@parameters/events/@type c:type GdkEventMask
+set-attr Gtk/Widget/set_events/@parameters/events/@type name Gdk.EventMask
+set-attr Gtk/Widget/set_events/@parameters/events/@type c:type GdkEventMask
+
 if osx
     # Not supported in Quartz version of Gtk
     ignore drag_set_icon_gicon
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:              3.0.19
+version:              3.0.20
 synopsis:             Gtk bindings
 description:          Bindings for Gtk, autogenerated by haskell-gi.
 homepage:             https://github.com/haskell-gi/haskell-gi