diff --git a/reactos/drivers/wdm/audio/backpln/portcls/port_wavertstream.cpp b/reactos/drivers/wdm/audio/backpln/portcls/port_wavertstream.cpp
index b98f7b5beef..f06945d8a01 100644
--- a/reactos/drivers/wdm/audio/backpln/portcls/port_wavertstream.cpp
+++ b/reactos/drivers/wdm/audio/backpln/portcls/port_wavertstream.cpp
@@ -161,7 +161,7 @@ CPortWaveRTStreamInit::GetPhysicalPageAddress(
         return RtlConvertUlongToLargeInteger(0);
     }
 
-    Buffer = (PVOID)UlongToPtr(PtrToUlong(MmGetSystemAddressForMdlSafe(MemoryDescriptorList, LowPagePriority)) + Index * PAGE_SIZE);
+    Buffer = (PUCHAR)MmGetSystemAddressForMdlSafe(MemoryDescriptorList, LowPagePriority) + (Index * PAGE_SIZE);
 
     Addr = MmGetPhysicalAddress(Buffer);
     Address->QuadPart = Addr.QuadPart;