diff --git a/src/libeis-device.c b/src/libeis-device.c
index 0df7bfa..20e9e68 100644
--- a/src/libeis-device.c
+++ b/src/libeis-device.c
@@ -44,6 +44,10 @@ OBJECT_IMPLEMENT_UNREF(eis_device);
 OBJECT_IMPLEMENT_CREATE(eis_device);
 static
 OBJECT_IMPLEMENT_PARENT(eis_device, eis_client);
+_public_
+OBJECT_IMPLEMENT_GETTER(eis_device, user_data, void *);
+_public_
+OBJECT_IMPLEMENT_SETTER(eis_device, user_data, void *);
 
 _public_ struct eis_client *
 eis_device_get_client(struct eis_device *device)
diff --git a/src/libeis-private.h b/src/libeis-private.h
index aa44ca8..6751c16 100644
--- a/src/libeis-private.h
+++ b/src/libeis-private.h
@@ -92,6 +92,7 @@ struct eis_device {
 	uint32_t id;
 	enum eis_device_state state;
 	uint32_t capabilities;
+	void *user_data;
 
 	struct {
 		struct dimensions dim;
diff --git a/src/libeis.h b/src/libeis.h
index 6e263ca..1f5a317 100644
--- a/src/libeis.h
+++ b/src/libeis.h
@@ -286,6 +286,12 @@ eis_device_ref(struct eis_device *device);
 struct eis_device *
 eis_device_unref(struct eis_device *device);
 
+void *
+eis_device_get_user_data(struct eis_device *eis_device);
+
+void
+eis_device_set_user_data(struct eis_device *eis_device, void *user_data);
+
 /**
  * Return the name of the device. The return value of this function may change after
  * eis_device_set_name(), a caller should keep a copy of it where required rather than the