diff --git a/spi.c b/spi.c
index 48be29a..29c202c 100644
--- a/spi.c
+++ b/spi.c
@@ -281,6 +281,11 @@
 	    GENERIC_DEVICE_ID == flash->model_id)
 		return 1;
 
+	/* Test if there is any vendor ID. */
+	if (GENERIC_MANUF_ID == flash->manufacture_id &&
+	    id1 != 0xff)
+		return 1;
+
 	return 0;
 }
 
@@ -340,6 +345,11 @@
 	    GENERIC_DEVICE_ID == flash->model_id)
 		return 1;
 
+	/* Test if there is any vendor ID. */
+	if (GENERIC_MANUF_ID == flash->manufacture_id &&
+	    id1 != 0xff)
+		return 1;
+
 	return 0;
 }