diff --git a/MdePkg/Library/BaseLib/Math64.c b/MdePkg/Library/BaseLib/Math64.c
index 83d7684721..9624cf9002 100644
--- a/MdePkg/Library/BaseLib/Math64.c
+++ b/MdePkg/Library/BaseLib/Math64.c
@@ -86,7 +86,7 @@ InternalMathARShiftU64 (
   //
   // Test if this compiler supports arithmetic shift
   //
-  TestValue = (((-1) << (sizeof (-1) * 8 - 1)) >> (sizeof (-1) * 8 - 1));
+  TestValue = (INTN)((INT64)(1ULL << 63) >> 63);
   if (TestValue == -1) {
     //
     // Arithmetic shift is supported