diff --git a/CorebootModulePkg/CbSupportPei/CbSupportPei.c b/CorebootModulePkg/CbSupportPei/CbSupportPei.c
index d51553dbc6..49488438a2 100644
--- a/CorebootModulePkg/CbSupportPei/CbSupportPei.c
+++ b/CorebootModulePkg/CbSupportPei/CbSupportPei.c
@@ -238,7 +238,7 @@ CbPeiEntryPoint (
        EFI_RESOURCE_ATTRIBUTE_WRITE_THROUGH_CACHEABLE |
        EFI_RESOURCE_ATTRIBUTE_WRITE_BACK_CACHEABLE
     ),
-    (EFI_PHYSICAL_ADDRESS)(0x100000000),
+    (EFI_PHYSICAL_ADDRESS)(0x100000000ULL),
     HighMemorySize
     );  	
   }