diff --git a/reactos/ntoskrnl/mm/virtual.c b/reactos/ntoskrnl/mm/virtual.c
index ba0a2eb1967..81bed85ee7d 100644
--- a/reactos/ntoskrnl/mm/virtual.c
+++ b/reactos/ntoskrnl/mm/virtual.c
@@ -70,7 +70,7 @@ MiDoMappedCopy(IN PEPROCESS SourceProcess,
     PFN_NUMBER MdlBuffer[(sizeof(MDL) / sizeof(PFN_NUMBER)) + MI_MAPPED_COPY_PAGES + 1];
     PMDL Mdl = (PMDL)MdlBuffer;
     ULONG TotalSize, CurrentSize, RemainingSize;
-    BOOLEAN FailedInProbe = FALSE, FailedInMapping = FALSE, FailedInMoving;
+    volatile BOOLEAN FailedInProbe = FALSE, FailedInMapping = FALSE, FailedInMoving;
     BOOLEAN PagesLocked;
     PVOID CurrentAddress = SourceAddress, CurrentTargetAddress = TargetAddress;
     PVOID MdlAddress;
@@ -225,7 +225,7 @@ MiDoPoolCopy(IN PEPROCESS SourceProcess,
 {
     UCHAR StackBuffer[MI_POOL_COPY_BYTES];
     ULONG TotalSize, CurrentSize, RemainingSize;
-    BOOLEAN FailedInProbe = FALSE, FailedInMoving, HavePoolAddress = FALSE;
+    volatile BOOLEAN FailedInProbe = FALSE, FailedInMoving, HavePoolAddress = FALSE;
     PVOID CurrentAddress = SourceAddress, CurrentTargetAddress = TargetAddress;
     PVOID PoolAddress;
     KAPC_STATE ApcState;