diff --git a/UnixPkg/UnixFlashMapPei/FlashMap.c b/UnixPkg/UnixFlashMapPei/FlashMap.c
index 9e96ac2425..d3a15cb814 100644
--- a/UnixPkg/UnixFlashMapPei/FlashMap.c
+++ b/UnixPkg/UnixFlashMapPei/FlashMap.c
@@ -38,8 +38,8 @@ Abstract:
 EFI_STATUS
 EFIAPI
 PeimInitializeFlashMap (
-  IN EFI_FFS_FILE_HEADER       *FfsHeader,
-  IN EFI_PEI_SERVICES          **PeiServices
+  IN       EFI_PEI_FILE_HANDLE       FileHandle,
+  IN CONST EFI_PEI_SERVICES          **PeiServices
   )
 /*++