diff --git a/drivers/staging/greybus/core.c b/drivers/staging/greybus/core.c
index 6c4107e20762..67628719f8d1 100644
--- a/drivers/staging/greybus/core.c
+++ b/drivers/staging/greybus/core.c
@@ -294,6 +294,7 @@ static void free_hd(struct kref *kref)
 	hd = container_of(kref, struct greybus_host_device, kref);
 
 	kfree(hd);
+	mutex_unlock(&hd_mutex);
 }
 
 struct greybus_host_device *greybus_create_hd(struct greybus_host_driver *driver,