diff --git a/common/criteria_lexer.mll b/common/criteria_lexer.mll

index 71f9178..e5a2376 100644

--- a/common/criteria_lexer.mll

+++ b/common/criteria_lexer.mll

@@ -18,7 +18,7 @@

     let c = Lexing.lexeme_char lexbuf 2 in (* the delimiter can be any character *)

     (* find the terminating delimiter *)

     let endpos =

-      try String.index_from lexbuf.lex_buffer (lexbuf.lex_start_pos + 3) c with

+      try String.index_from (Lexing.lexeme lexbuf) (lexbuf.lex_start_pos + 3) c with

       |Invalid_argument _ ->

           raise (Format822.Syntax_error (

             Format822.error lexbuf "String too short"))

@@ -27,7 +27,7 @@

             Format822.error lexbuf (Printf.sprintf "cannot find: %c" c)))

     in

     let len = endpos - (lexbuf.lex_start_pos + 3) in

-    let s = String.sub lexbuf.lex_buffer (lexbuf.lex_start_pos + 3) len in

+    let s = String.sub (Lexing.lexeme lexbuf) (lexbuf.lex_start_pos + 3) len in

     lexbuf.Lexing.lex_curr_pos <- lexbuf.Lexing.lex_start_pos + ((String.length s)+4);

     s