diff --git a/OvmfPkg/QemuFlashFvbServicesRuntimeDxe/FwBlockServiceDxe.c b/OvmfPkg/QemuFlashFvbServicesRuntimeDxe/FwBlockServiceDxe.c
index 1f285e0083..ab40087a84 100644
--- a/OvmfPkg/QemuFlashFvbServicesRuntimeDxe/FwBlockServiceDxe.c
+++ b/OvmfPkg/QemuFlashFvbServicesRuntimeDxe/FwBlockServiceDxe.c
@@ -205,11 +205,10 @@ MarkIoMemoryRangeForRuntimeAccess (
   // memory range.
   //
   if (MemEncryptSevIsEnabled ()) {
-    Status = MemEncryptSevClearPageEncMask (
+    Status = MemEncryptSevClearMmioPageEncMask (
                0,
                BaseAddress,
-               EFI_SIZE_TO_PAGES (Length),
-               FALSE
+               EFI_SIZE_TO_PAGES (Length)
                );
     ASSERT_EFI_ERROR (Status);
   }
diff --git a/OvmfPkg/QemuFlashFvbServicesRuntimeDxe/QemuFlashSmm.c b/OvmfPkg/QemuFlashFvbServicesRuntimeDxe/QemuFlashSmm.c
index 7eb80bfeff..ea75b489c7 100644
--- a/OvmfPkg/QemuFlashFvbServicesRuntimeDxe/QemuFlashSmm.c
+++ b/OvmfPkg/QemuFlashFvbServicesRuntimeDxe/QemuFlashSmm.c
@@ -38,11 +38,10 @@ QemuFlashBeforeProbe (
   // C-bit on flash ranges from SMM page table.
   //
 
-  Status = MemEncryptSevClearPageEncMask (
+  Status = MemEncryptSevClearMmioPageEncMask (
              0,
              BaseAddress,
-             EFI_SIZE_TO_PAGES (FdBlockSize * FdBlockCount),
-             FALSE
+             EFI_SIZE_TO_PAGES (FdBlockSize * FdBlockCount)
              );
   ASSERT_EFI_ERROR (Status);
 }