diff --git a/MdePkg/Library/BaseLib/Synchronization.c b/MdePkg/Library/BaseLib/Synchronization.c
index 5033133224..0457f3ab89 100644
--- a/MdePkg/Library/BaseLib/Synchronization.c
+++ b/MdePkg/Library/BaseLib/Synchronization.c
@@ -236,7 +236,7 @@ AcquireSpinLockOrFail (
   IN OUT  SPIN_LOCK                 *SpinLock
   )
 {
-  SPIN_LOCK    LockValue;
+  volatile SPIN_LOCK    LockValue;
 
   ASSERT (SpinLock != NULL);