diff --git a/src/libei-device.c b/src/libei-device.c
index f8b6b4e..b949ae1 100644
--- a/src/libei-device.c
+++ b/src/libei-device.c
@@ -49,6 +49,10 @@ static
 OBJECT_IMPLEMENT_PARENT(ei_device, ei);
 _public_
 OBJECT_IMPLEMENT_GETTER(ei_device, name, const char *);
+_public_
+OBJECT_IMPLEMENT_GETTER(ei_device, user_data, void *);
+_public_
+OBJECT_IMPLEMENT_SETTER(ei_device, user_data, void *);
 
 _public_ struct ei*
 ei_device_get_context(struct ei_device *device)
diff --git a/src/libei-private.h b/src/libei-private.h
index dd9620d..8353e05 100644
--- a/src/libei-private.h
+++ b/src/libei-private.h
@@ -66,6 +66,7 @@ enum ei_device_state {
 
 struct ei_device {
 	struct object object;
+	void *user_data;
 	struct list link;
 	uint32_t id;
 	enum ei_device_state state;
diff --git a/src/libei.h b/src/libei.h
index 6f62458..9c4d0a9 100644
--- a/src/libei.h
+++ b/src/libei.h
@@ -289,6 +289,12 @@ ei_device_unref(struct ei_device *device);
 struct ei_device *
 ei_device_new(struct ei *ei);
 
+void
+ei_device_set_user_data(struct ei_device *device, void *user_data);
+
+void *
+ei_device_get_user_data(struct ei_device *device);
+
 /**
  * Set the name for this device. This is a suggestion only, the server may
  * the name and assign a different one (or none). Use ei_device_get_name()