diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.h b/UefiCpuPkg/Library/MpInitLib/MpLib.h
index 179f8e585b..11e0d2661f 100644
--- a/UefiCpuPkg/Library/MpInitLib/MpLib.h
+++ b/UefiCpuPkg/Library/MpInitLib/MpLib.h
@@ -357,7 +357,8 @@ typedef
IN UINTN StackStart
);
-extern EFI_GUID mCpuInitMpLibHobGuid;
+extern EFI_GUID mCpuInitMpLibHobGuid;
+extern volatile UINT32 mNumberToFinish;
[Ray] It's very good that you keep other global variables in MpLib.c only.
Reviewed-by: Ray Ni <ray.ni@intel.com>