diff --git a/spi25.c b/spi25.c
index 673bdf5..af4b6db 100644
--- a/spi25.c
+++ b/spi25.c
@@ -156,7 +156,7 @@
 		return 1;
 
 	/* Test if there is any vendor ID. */
-	if (GENERIC_MANUF_ID == chip->manufacture_id && id1 != 0xff)
+	if (GENERIC_MANUF_ID == chip->manufacture_id && id1 != 0xff && id1 != 0x00)
 		return 1;
 
 	return 0;
@@ -212,7 +212,7 @@
 		return 1;
 
 	/* Test if there is any vendor ID. */
-	if (GENERIC_MANUF_ID == chip->manufacture_id && id1 != 0xff)
+	if (GENERIC_MANUF_ID == chip->manufacture_id && id1 != 0xff && id1 != 0x00)
 		return 1;
 
 	return 0;