diff --git a/MdeModulePkg/Library/UefiHiiLib/HiiLib.c b/MdeModulePkg/Library/UefiHiiLib/HiiLib.c
index 2ad85ad75e..c6e1fe12ad 100644
--- a/MdeModulePkg/Library/UefiHiiLib/HiiLib.c
+++ b/MdeModulePkg/Library/UefiHiiLib/HiiLib.c
@@ -1411,7 +1411,7 @@ InternalHiiValidateCurrentSetting (
           // Get Offset by Question header
           //
           Offset = IfrCheckBox->Question.VarStoreInfo.VarOffset;
-          Width  = sizeof (BOOLEAN);
+          Width  = (UINT16) sizeof (BOOLEAN);
           //
           // Check whether this question is in current block array.
           //