diff --git a/EmulatorPkg/Win/Host/WinThunk.c b/EmulatorPkg/Win/Host/WinThunk.c
index e82735c6a0..0abe4727e0 100644
--- a/EmulatorPkg/Win/Host/WinThunk.c
+++ b/EmulatorPkg/Win/Host/WinThunk.c
@@ -264,11 +264,11 @@ volatile BOOLEAN  mInterruptEnabled = FALSE;
 VOID
 CALLBACK
 MMTimerThread (
-  UINT   wTimerID,
-  UINT   msg,
-  DWORD  dwUser,
-  DWORD  dw1,
-  DWORD  dw2
+  UINT       wTimerID,
+  UINT       msg,
+  DWORD_PTR  dwUser,
+  DWORD_PTR  dw1,
+  DWORD_PTR  dw2
   )
 {
   UINT32  CurrentTick;