diff --git a/reactos/ntoskrnl/mm/ARM3/init.c b/reactos/ntoskrnl/mm/ARM3/init.c
index 07812264ad1..55d7db4dbff 100644
--- a/reactos/ntoskrnl/mm/ARM3/init.c
+++ b/reactos/ntoskrnl/mm/ARM3/init.c
@@ -121,7 +121,7 @@ MiSyncARM3WithROS(IN PVOID AddressStart,
         //
         // This both odious and heinous
         //
-        extern PULONG MmGlobalKernelPageDirectory;
+        extern ULONG MmGlobalKernelPageDirectory[1024];
         MmGlobalKernelPageDirectory[Pde] = ((PULONG)PAGEDIRECTORY_MAP)[Pde];
         Pde++;
     }