diff --git a/reactos/ntoskrnl/mm/ARM3/mdlsup.c b/reactos/ntoskrnl/mm/ARM3/mdlsup.c
index 6d63db132b7..b3449a366dc 100644
--- a/reactos/ntoskrnl/mm/ARM3/mdlsup.c
+++ b/reactos/ntoskrnl/mm/ARM3/mdlsup.c
@@ -1343,7 +1343,7 @@ MmUnlockPages(IN PMDL Mdl)
             InterlockedExchangeAddSizeT(&MmSystemLockPagesCount, -1);
             
             /* Do the last dereference, we're done here */
-            MiDecrementReferenceCount(Pfn1, *MdlPages);
+            MiDecrementReferenceCount(Pfn1, MiGetPfnEntryIndex(Pfn1));
         }
         else
         {