diff --git a/UefiCpuPkg/CpuDxe/CpuMp.c b/UefiCpuPkg/CpuDxe/CpuMp.c
index e5d2f5f7e2..fa0ef37b92 100644
--- a/UefiCpuPkg/CpuDxe/CpuMp.c
+++ b/UefiCpuPkg/CpuDxe/CpuMp.c
@@ -1193,7 +1193,7 @@ ProcessorToIdleState (
   UINTN                 ProcessorNumber;
   CPU_DATA_BLOCK        *CpuData;
   EFI_AP_PROCEDURE      Procedure;
-  VOID                  *ProcedureArgument;
+  volatile VOID         *ProcedureArgument;
 
   AsmApDoneWithCommonStack ();
 
@@ -1231,7 +1231,7 @@ ProcessorToIdleState (
     if (Procedure != NULL) {
       SetApState (CpuData, CpuStateBusy);
 
-      Procedure (ProcedureArgument);
+      Procedure ((VOID*) ProcedureArgument);
 
       GetMpSpinLock (CpuData);
       CpuData->Procedure = NULL;
diff --git a/UefiCpuPkg/CpuDxe/CpuMp.h b/UefiCpuPkg/CpuDxe/CpuMp.h
index cb3460f355..021b80821e 100644
--- a/UefiCpuPkg/CpuDxe/CpuMp.h
+++ b/UefiCpuPkg/CpuDxe/CpuMp.h
@@ -94,8 +94,8 @@ typedef struct {
   INTN                           LockSelf;
   volatile CPU_STATE             State;
 
-  EFI_AP_PROCEDURE               Procedure;
-  VOID                           *Parameter;
+  volatile EFI_AP_PROCEDURE      Procedure;
+  volatile VOID*                 Parameter;
   BOOLEAN                        *Finished;
   INTN                           Timeout;
   EFI_EVENT                      WaitEvent;