diff --git a/MdeModulePkg/Bus/Isa/Ps2MouseDxe/CommPs2.h b/MdeModulePkg/Bus/Isa/Ps2MouseDxe/CommPs2.h
index 6cf814e8f0..26535fc948 100644
--- a/MdeModulePkg/Bus/Isa/Ps2MouseDxe/CommPs2.h
+++ b/MdeModulePkg/Bus/Isa/Ps2MouseDxe/CommPs2.h
@@ -266,7 +266,7 @@ PS2MouseGetPacket (
 **/
 EFI_STATUS
 PS2MouseRead (
-  OUT VOID                                *Buffer,
+  OUT UINT8                               *Buffer,
   IN OUT UINTN                            *BufSize,
   IN  UINTN                               State
   );