diff --git a/ntoskrnl/include/internal/mm.h b/ntoskrnl/include/internal/mm.h
index 6782fc1ab39..2548fc66ef9 100644
--- a/ntoskrnl/include/internal/mm.h
+++ b/ntoskrnl/include/internal/mm.h
@@ -269,6 +269,9 @@ typedef struct _MEMORY_AREA
     } SectionData;
 } MEMORY_AREA, *PMEMORY_AREA;
 
+#define MI_SET_MEMORY_AREA_VAD(Vad) do { (Vad)->u.VadFlags.Spare |= 1; } while (0)
+#define MI_IS_MEMORY_AREA_VAD(Vad) (((Vad)->u.VadFlags.Spare & 1) != 0)
+
 typedef struct _MM_RMAP_ENTRY
 {
    struct _MM_RMAP_ENTRY* Next;
diff --git a/ntoskrnl/mm/ARM3/procsup.c b/ntoskrnl/mm/ARM3/procsup.c
index 6c11bb4cf7d..397b3b71862 100644
--- a/ntoskrnl/mm/ARM3/procsup.c
+++ b/ntoskrnl/mm/ARM3/procsup.c
@@ -1293,7 +1293,7 @@ MmCleanProcessAddressSpace(IN PEPROCESS Process)
         Vad = (PMMVAD)VadTree->BalancedRoot.RightChild;
 
         /* Check for old-style memory areas */
-        if (Vad->u.VadFlags.Spare == 1)
+        if (MI_IS_MEMORY_AREA_VAD(Vad))
         {
             /* Let RosMm handle this */
             MiRosCleanupMemoryArea(Process, Vad);
diff --git a/ntoskrnl/mm/ARM3/section.c b/ntoskrnl/mm/ARM3/section.c
index 8be6b0aab3e..73f95adb750 100644
--- a/ntoskrnl/mm/ARM3/section.c
+++ b/ntoskrnl/mm/ARM3/section.c
@@ -778,6 +778,7 @@ MiRemoveMappedView(IN PEPROCESS CurrentProcess,
     ASSERT(Vad->u2.VadFlags2.ExtendableFile == FALSE);
     ASSERT(ControlArea);
     ASSERT(ControlArea->FilePointer == NULL);
+    ASSERT(!MI_IS_MEMORY_AREA_VAD(Vad));
 
     /* Delete the actual virtual memory pages */
     MiDeleteVirtualAddresses(Vad->StartingVpn << PAGE_SHIFT,
@@ -1564,7 +1565,7 @@ MiGetFileObjectForVad(
     PFILE_OBJECT FileObject;
 
     /* Check if this is a RosMm memory area */
-    if (Vad->u.VadFlags.Spare != 0)
+    if (MI_IS_MEMORY_AREA_VAD(Vad))
     {
         PMEMORY_AREA MemoryArea = (PMEMORY_AREA)Vad;
 
diff --git a/ntoskrnl/mm/ARM3/vadnode.c b/ntoskrnl/mm/ARM3/vadnode.c
index 53b8fa83dbd..a4820dac5c8 100644
--- a/ntoskrnl/mm/ARM3/vadnode.c
+++ b/ntoskrnl/mm/ARM3/vadnode.c
@@ -213,7 +213,7 @@ MiInsertNode(IN PMM_AVL_TABLE Table,
 
     /* Now insert an ARM3 MEMORY_AREA for this node, unless the insert was already from the MEMORY_AREA code */
     Vad = (PMMVAD_LONG)NewNode;
-    if (Vad->u.VadFlags.Spare == 0)
+    if (!MI_IS_MEMORY_AREA_VAD(Vad))
     {
         NTSTATUS Status;
         PMEMORY_AREA MemoryArea;
@@ -460,7 +460,7 @@ MiRemoveNode(IN PMMADDRESS_NODE Node,
 
     /* Free the node from ReactOS view as well */
     Vad = (PMMVAD_LONG)Node;
-    if ((Table != &MmSectionBasedRoot) && (Vad->u.VadFlags.Spare == 0))
+    if ((Table != &MmSectionBasedRoot) && !MI_IS_MEMORY_AREA_VAD(Vad))
     {
         PMEMORY_AREA MemoryArea;
         PEPROCESS Process;
diff --git a/ntoskrnl/mm/ARM3/virtual.c b/ntoskrnl/mm/ARM3/virtual.c
index 3b7f0f722f0..cb38b4a1502 100644
--- a/ntoskrnl/mm/ARM3/virtual.c
+++ b/ntoskrnl/mm/ARM3/virtual.c
@@ -546,7 +546,7 @@ MiDeleteVirtualAddresses(IN ULONG_PTR Va,
     PSUBSECTION Subsection;
 
     /* Get out if this is a fake VAD, RosMm will free the marea pages */
-    if ((Vad) && (Vad->u.VadFlags.Spare == 1)) return;
+    if ((Vad) && MI_IS_MEMORY_AREA_VAD(Vad)) return;
 
     /* Get the current process */
     CurrentProcess = PsGetCurrentProcess();
diff --git a/ntoskrnl/mm/marea.c b/ntoskrnl/mm/marea.c
index 22c2369448c..c1c11490c23 100644
--- a/ntoskrnl/mm/marea.c
+++ b/ntoskrnl/mm/marea.c
@@ -92,7 +92,7 @@ MmLocateMemoryAreaByRegion(
     }
 
     Vad = (PMMVAD_LONG)Node;
-    if (Vad->u.VadFlags.Spare == 0)
+    if (!MI_IS_MEMORY_AREA_VAD(Vad))
     {
         /* Check if this is VM VAD */
         if (Vad->ControlArea == NULL)
@@ -157,7 +157,6 @@ MmInsertMemoryArea(
 {
     PEPROCESS Process = MmGetAddressSpaceOwner(AddressSpace);
 
-    marea->VadNode.u.VadFlags.Spare = 1;
     marea->VadNode.u.VadFlags.Protection = MiMakeProtectionMask(Protect);
 
     /* Build a lame VAD if this is a user-space allocation */
@@ -334,9 +333,10 @@ MmFreeMemoryArea(
 #endif
 
             /* MmCleanProcessAddressSpace might have removed it (and this would be MmDeleteProcessAddressSpace) */
-            ASSERT(MemoryArea->VadNode.u.VadFlags.Spare != 0);
-            if (((PMMVAD)MemoryArea->Vad)->u.VadFlags.Spare == 1)
+            ASSERT(MI_IS_MEMORY_AREA_VAD(&MemoryArea->VadNode));
+            if (MI_IS_MEMORY_AREA_VAD((PMMVAD)MemoryArea->Vad))
             {
+                ASSERT((PMMVAD)MemoryArea->Vad == &MemoryArea->VadNode);
                 MiLockProcessWorkingSet(PsGetCurrentProcess(), PsGetCurrentThread());
                 MiRemoveNode((PMMADDRESS_NODE)&MemoryArea->VadNode, &Process->VadRoot);
                 MiUnlockProcessWorkingSet(PsGetCurrentProcess(), PsGetCurrentThread());
@@ -439,6 +439,7 @@ MmCreateMemoryArea(PMMSUPPORT AddressSpace,
     MemoryArea->Flags = AllocationFlags;
     MemoryArea->Magic = 'erAM';
     MemoryArea->DeleteInProgress = FALSE;
+    MI_SET_MEMORY_AREA_VAD(&MemoryArea->VadNode);
 
     if (*BaseAddress == 0)
     {