diff --git a/stm50flw0x0x.c b/stm50flw0x0x.c
index 67cf62c..c06bab9 100644
--- a/stm50flw0x0x.c
+++ b/stm50flw0x0x.c
@@ -80,7 +80,7 @@
 	*(volatile uint8_t *)(bios + 0x5555) = 0xF0;
 	myusec_delay(40);
 
-	printf_debug("%s: id1 0x%x, id2 0x%x\n", __FUNCTION__, largeid1,
+	printf_debug("%s: id1 0x%02x, id2 0x%02x\n", __FUNCTION__, largeid1,
 		     largeid2);
 
 	if (largeid1 != flash->manufacture_id || largeid2 != flash->model_id)