diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index d07875a11be0f2..61102d124aa3e1 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -159,6 +159,8 @@
 
 #define MSR_IA32_OC_MAILBOX		0x00000150
 
+#define MSR_IA32_OC_MAILBOX		0x00000150
+
 #define MSR_IA32_SYSENTER_CS		0x00000174
 #define MSR_IA32_SYSENTER_ESP		0x00000175
 #define MSR_IA32_SYSENTER_EIP		0x00000176