diff --git a/MdeModulePkg/Library/DeviceManagerUiLib/DeviceManager.c b/MdeModulePkg/Library/DeviceManagerUiLib/DeviceManager.c
index 5cc527679a..0540e6fa8a 100644
--- a/MdeModulePkg/Library/DeviceManagerUiLib/DeviceManager.c
+++ b/MdeModulePkg/Library/DeviceManagerUiLib/DeviceManager.c
@@ -619,7 +619,7 @@ CreateDeviceManagerForm(
         TokenHelp = HiiSetString (HiiHandle, 0, String, NULL);
         FreePool (String);
 
-        FormSetGuid = ((EFI_IFR_FORM_SET *)Ptr)->Guid;
+        CopyMem (&FormSetGuid, &((EFI_IFR_FORM_SET *) Ptr)->Guid, sizeof (EFI_GUID));
 
         //
         // Network device process