diff --git a/src/chipset/opti5x7.c b/src/chipset/opti5x7.c
index b31996c85..494fdee64 100644
--- a/src/chipset/opti5x7.c
+++ b/src/chipset/opti5x7.c
@@ -35,7 +35,7 @@
 typedef struct opti5x7_t {
     uint8_t idx;
     uint8_t is_pci;
-    uint8_t regs[16];
+    uint8_t regs[18];
 } opti5x7_t;
 
 #ifdef ENABLE_OPTI5X7_LOG