diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.h b/UefiCpuPkg/Library/MpInitLib/MpLib.h
index 7d84a56fbc..f8c52426dd 100644
--- a/UefiCpuPkg/Library/MpInitLib/MpLib.h
+++ b/UefiCpuPkg/Library/MpInitLib/MpLib.h
@@ -477,7 +477,7 @@ WakeUpAP (
   IN UINTN             ProcessorNumber,
   IN EFI_AP_PROCEDURE  Procedure               OPTIONAL,
   IN VOID              *ProcedureArgument      OPTIONAL,
-  IN BOOLEAN           WakeUpDisabledAps       OPTIONAL
+  IN BOOLEAN           WakeUpDisabledAps
   );
 
 /**