diff --git a/src/include/device/pci_def.h b/src/include/device/pci_def.h
index c49e4eb..ef3427b 100644
--- a/src/include/device/pci_def.h
+++ b/src/include/device/pci_def.h
@@ -18,6 +18,7 @@
 #define  PCI_COMMAND_WAIT 	0x80	/* Enable address/data stepping */
 #define  PCI_COMMAND_SERR	0x100	/* Enable SERR */
 #define  PCI_COMMAND_FAST_BACK	0x200	/* Enable back-to-back writes */
+#define  PCI_COMMAND_INT_DISABLE 0x400	/* Interrupt disable */
 
 #define PCI_STATUS		0x06	/* 16 bits */
 #define  PCI_STATUS_CAP_LIST	0x10	/* Support Capability List */