diff --git a/MdePkg/Library/BaseLib/Synchronization.c b/MdePkg/Library/BaseLib/Synchronization.c
index 0457f3ab89..18812e242f 100644
--- a/MdePkg/Library/BaseLib/Synchronization.c
+++ b/MdePkg/Library/BaseLib/Synchronization.c
@@ -272,7 +272,7 @@ ReleaseSpinLock (
   IN OUT  SPIN_LOCK                 *SpinLock
   )
 {
-  SPIN_LOCK    LockValue;
+  volatile SPIN_LOCK    LockValue;
 
   ASSERT (SpinLock != NULL);