diff --git a/MdePkg/Library/PeiIoLibCpuIo/IoLib.c b/MdePkg/Library/PeiIoLibCpuIo/IoLib.c
index e047ffa639..066ceddbfb 100644
--- a/MdePkg/Library/PeiIoLibCpuIo/IoLib.c
+++ b/MdePkg/Library/PeiIoLibCpuIo/IoLib.c
@@ -521,7 +521,7 @@ MmioRead64 (
   //
   // Make sure Address is aligned on a 64-bit boundary.
   //
-  ASSERT ((Address & 7) == (sizeof (UINT64) - 1));
+  ASSERT ((Address & (sizeof (UINT64) - 1)) == 0);
   return CpuIo->MemRead64 (PeiServices, CpuIo, (UINT64) Address);
 
 }