diff --git a/ntoskrnl/mm/ARM3/mminit.c b/ntoskrnl/mm/ARM3/mminit.c
index 25c37dcc9ac..63be4f66ebc 100644
--- a/ntoskrnl/mm/ARM3/mminit.c
+++ b/ntoskrnl/mm/ARM3/mminit.c
@@ -1202,7 +1202,7 @@ MiAddHalIoMappings(VOID)
 
     /* Check how many PDEs the heap has */
     PointerPde = MiAddressToPde(BaseAddress);
-    PdeCount = PDE_COUNT - ADDR_TO_PDE_OFFSET(BaseAddress);
+    PdeCount = PDE_COUNT - MiGetPdeOffset(BaseAddress);
     for (i = 0; i < PdeCount; i++)
     {
         /* Does the HAL own this mapping? */