diff --git a/src/hotplug-sniffer/shell-mime-sniffer.c b/src/hotplug-sniffer/shell-mime-sniffer.c
index 723249692..b5be4027d 100644
--- a/src/hotplug-sniffer/shell-mime-sniffer.c
+++ b/src/hotplug-sniffer/shell-mime-sniffer.c
@@ -43,8 +43,6 @@
 #define DIRECTORY_LOAD_ITEMS_PER_CALLBACK 100
 #define HIGH_SCORE_RATIO 0.10
 
-G_DEFINE_TYPE (ShellMimeSniffer, shell_mime_sniffer, G_TYPE_OBJECT);
-
 enum {
   PROP_FILE = 1,
   NUM_PROPERTIES
@@ -72,6 +70,15 @@ typedef struct {
   gint total_items;
 } DeepCountState;
 
+typedef struct _ShellMimeSnifferPrivate   ShellMimeSnifferPrivate;
+
+struct _ShellMimeSniffer
+{
+  GObject parent_instance;
+
+  ShellMimeSnifferPrivate *priv;
+};
+
 struct _ShellMimeSnifferPrivate {
   GFile *file;
 
@@ -82,6 +89,8 @@ struct _ShellMimeSnifferPrivate {
   gchar **sniffed_mime;
 };
 
+G_DEFINE_TYPE_WITH_PRIVATE (ShellMimeSniffer, shell_mime_sniffer, G_TYPE_OBJECT);
+
 static void deep_count_load (DeepCountState *state,
                              GFile *file);
 
@@ -550,17 +559,13 @@ shell_mime_sniffer_class_init (ShellMimeSnifferClass *klass)
                          G_TYPE_FILE,
                          G_PARAM_READWRITE);
 
-  g_type_class_add_private (klass, sizeof (ShellMimeSnifferPrivate));
   g_object_class_install_properties (oclass, NUM_PROPERTIES, properties);
 }
 
 static void
 shell_mime_sniffer_init (ShellMimeSniffer *self)
 {
-  self->priv =
-    G_TYPE_INSTANCE_GET_PRIVATE (self,
-                                 SHELL_TYPE_MIME_SNIFFER,
-                                 ShellMimeSnifferPrivate);
+  self->priv = shell_mime_sniffer_get_instance_private (self);
   init_mimetypes ();
 }
 
diff --git a/src/hotplug-sniffer/shell-mime-sniffer.h b/src/hotplug-sniffer/shell-mime-sniffer.h
index 217ed67e5..3936eef14 100644
--- a/src/hotplug-sniffer/shell-mime-sniffer.h
+++ b/src/hotplug-sniffer/shell-mime-sniffer.h
@@ -27,30 +27,9 @@
 
 G_BEGIN_DECLS
 
-#define SHELL_TYPE_MIME_SNIFFER            (shell_mime_sniffer_get_type ())
-#define SHELL_MIME_SNIFFER(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), SHELL_TYPE_MIME_SNIFFER, ShellMimeSniffer))
-#define SHELL_IS_MIME_SNIFFER(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), SHELL_TYPE_MIME_SNIFFER))
-#define SHELL_MIME_SNIFFER_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass),  SHELL_TYPE_MIME_SNIFFER, ShellMimeSnifferClass))
-#define SHELL_IS_MIME_SNIFFER_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass),  SHELL_TYPE_MIME_SNIFFER))
-#define SHELL_MIME_SNIFFER_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj),  SHELL_TYPE_MIME_SNIFFER, ShellMimeSnifferClass))
-
-typedef struct _ShellMimeSniffer          ShellMimeSniffer;
-typedef struct _ShellMimeSnifferPrivate   ShellMimeSnifferPrivate;
-typedef struct _ShellMimeSnifferClass     ShellMimeSnifferClass;
-
-struct _ShellMimeSniffer
-{
-  GObject parent_instance;
-
-  ShellMimeSnifferPrivate *priv;
-};
-
-struct _ShellMimeSnifferClass
-{
-  GObjectClass parent_class;
-};
-
-GType    shell_mime_sniffer_get_type     (void) G_GNUC_CONST;
+#define SHELL_TYPE_MIME_SNIFFER (shell_mime_sniffer_get_type ())
+G_DECLARE_FINAL_TYPE (ShellMimeSniffer, shell_mime_sniffer,
+                      SHELL, MIME_SNIFFER, GObject)
 
 ShellMimeSniffer *shell_mime_sniffer_new (GFile *file);