diff --git a/meson.build b/meson.build
index 18c49d6f..ecf1dc96 100644
--- a/meson.build
+++ b/meson.build
@@ -81,6 +81,7 @@ assert(cc.has_function('strerror'), '"strerror" not found')
 
 # options
 config_h.set('ENABLE_TRACING', enable_tracing)
+config_h.set('HANDY_USE_UNSTABLE_API', true)
 
 # _NL_TIME_FIRST_WEEKDAY is an enum and not a define
 nl_time_first_weekday_src = '''
diff --git a/src/gui/gcal-edit-dialog.c b/src/gui/gcal-edit-dialog.c
index a5881872..55a14066 100644
--- a/src/gui/gcal-edit-dialog.c
+++ b/src/gui/gcal-edit-dialog.c
@@ -45,7 +45,7 @@
 
 struct _GcalEditDialog
 {
-  GtkDialog         parent;
+  HdyDialog         parent;
 
   gboolean          writable;
 
@@ -134,7 +134,7 @@ static void          on_remove_alarm_button_clicked              (GtkButton
 static void          on_add_alarm_button_clicked_cb              (GtkWidget          *button,
                                                                   GcalEditDialog     *self);
 
-G_DEFINE_TYPE (GcalEditDialog, gcal_edit_dialog, GTK_TYPE_DIALOG)
+G_DEFINE_TYPE (GcalEditDialog, gcal_edit_dialog, HDY_TYPE_DIALOG)
 
 enum
 {
diff --git a/src/gui/gcal-edit-dialog.h b/src/gui/gcal-edit-dialog.h
index d4bea553..e4f44ec5 100644
--- a/src/gui/gcal-edit-dialog.h
+++ b/src/gui/gcal-edit-dialog.h
@@ -22,7 +22,7 @@
 #include "gcal-event.h"
 #include "gcal-manager.h"
 
-#include <gtk/gtk.h>
+#include <handy.h>
 
 G_BEGIN_DECLS
 
@@ -32,7 +32,7 @@ G_BEGIN_DECLS
 
 #define GCAL_TYPE_EDIT_DIALOG                (gcal_edit_dialog_get_type ())
 
-G_DECLARE_FINAL_TYPE (GcalEditDialog, gcal_edit_dialog, GCAL, EDIT_DIALOG, GtkDialog);
+G_DECLARE_FINAL_TYPE (GcalEditDialog, gcal_edit_dialog, GCAL, EDIT_DIALOG, HdyDialog);
 
 GtkWidget*           gcal_edit_dialog_new                     (void);
 
diff --git a/src/gui/gcal-edit-dialog.ui b/src/gui/gcal-edit-dialog.ui
index 94f2ea44..5c2fcfaf 100644
--- a/src/gui/gcal-edit-dialog.ui
+++ b/src/gui/gcal-edit-dialog.ui
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <interface>
-  <template class="GcalEditDialog" parent="GtkDialog">
+  <template class="GcalEditDialog" parent="HdyDialog">
     <property name="can_focus">False</property>
     <property name="resizable">False</property>
     <property name="modal">True</property>