diff --git a/MdeModulePkg/Library/UefiHiiLib/HiiString.c b/MdeModulePkg/Library/UefiHiiLib/HiiString.c
index cd4944152a..e10b1c72ee 100644
--- a/MdeModulePkg/Library/UefiHiiLib/HiiString.c
+++ b/MdeModulePkg/Library/UefiHiiLib/HiiString.c
@@ -199,6 +199,7 @@ HiiLibNewString (
   Status = EFI_SUCCESS;
 
   Languages = HiiLibGetSupportedLanguages (PackageList);
+  ASSERT (Languages != NULL);
 
   LangStrings = Languages;
   while (*LangStrings != 0) {