diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
index da21f69e7..b908fcda0 100644
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -104,6 +104,8 @@ struct ubi_device *ubi_get_device(int ubi_num)
 	struct ubi_device *ubi;
 
 	ubi = ubi_devices[ubi_num];
+	if (!ubi)
+		return NULL;
 
 	ubi->ref_count++;