diff --git a/src/passes/1-parser/cameligo/LexerMain.ml b/src/passes/1-parser/cameligo/LexerMain.ml
index 6c0729851..5ef471c37 100644
--- a/src/passes/1-parser/cameligo/LexerMain.ml
+++ b/src/passes/1-parser/cameligo/LexerMain.ml
@@ -1,4 +1,4 @@
-(** Driver for the CameLIGO lexer *)
+(* Driver for the CameLIGO lexer *)
 
 module IO =
   struct
@@ -11,4 +11,4 @@ module M = LexerUnit.Make (IO) (Lexer.Make (LexToken))
 let () =
   match M.trace () with
     Stdlib.Ok () -> ()
-  | Error msg -> Utils.highlight msg
+  | Error Region.{value; _} -> Utils.highlight value
diff --git a/src/passes/1-parser/pascaligo/LexerMain.ml b/src/passes/1-parser/pascaligo/LexerMain.ml
index f02b06642..32606118a 100644
--- a/src/passes/1-parser/pascaligo/LexerMain.ml
+++ b/src/passes/1-parser/pascaligo/LexerMain.ml
@@ -13,4 +13,4 @@ module M = LexerUnit.Make (IO) (Lexer.Make (LexToken))
 let () =
   match M.trace () with
     Stdlib.Ok () -> ()
-  | Error msg -> Utils.highlight msg
+  | Error Region.{value; _} -> Utils.highlight value
diff --git a/src/passes/1-parser/reasonligo/LexerMain.ml b/src/passes/1-parser/reasonligo/LexerMain.ml
index 8681f49e8..f0589990c 100644
--- a/src/passes/1-parser/reasonligo/LexerMain.ml
+++ b/src/passes/1-parser/reasonligo/LexerMain.ml
@@ -1,4 +1,4 @@
-(** Driver for the ReasonLIGO lexer *)
+(* Driver for the ReasonLIGO lexer *)
 
 module IO =
   struct
@@ -11,4 +11,4 @@ module M = LexerUnit.Make (IO) (Lexer.Make (LexToken))
 let () =
   match M.trace () with
     Stdlib.Ok () -> ()
-  | Error msg -> Utils.highlight msg
+  | Error Region.{value; _} -> Utils.highlight value
diff --git a/src/passes/1-parser/shared/Lexer.mll b/src/passes/1-parser/shared/Lexer.mll
index ca85a124e..2821acc85 100644
--- a/src/passes/1-parser/shared/Lexer.mll
+++ b/src/passes/1-parser/shared/Lexer.mll
@@ -823,17 +823,17 @@ and scan_utf8 thread state = parse
    context of a recognised lexeme (to enforce stylistic constraints or
    report special error patterns), we need to keep a hidden reference
    to a queue of recognised lexical units (that is, tokens and markup)
-   that acts as a mutable state between the calls to
-   [read_token]. When [read_token] is called, that queue is examined
-   first and, if it contains at least one token, that token is
-   returned; otherwise, the lexing buffer is scanned for at least one
-   more new token. That is the general principle: we put a high-level
-   buffer (our queue) on top of the low-level lexing buffer.
+   that acts as a mutable state between the calls to [read]. When
+   [read] is called, that queue is examined first and, if it contains
+   at least one token, that token is returned; otherwise, the lexing
+   buffer is scanned for at least one more new token. That is the
+   general principle: we put a high-level buffer (our queue) on top of
+   the low-level lexing buffer.
 
      One tricky and important detail is that we must make any parser
-   generated by Menhir (and calling [read_token]) believe that the
-   last region of the input source that was matched indeed corresponds
-   to the returned token, despite that many tokens and markup may have
+   generated by Menhir (and calling [read]) believe that the last
+   region of the input source that was matched indeed corresponds to
+   the returned token, despite that many tokens and markup may have
    been matched since it was actually read from the input. In other
    words, the parser requests a token that is taken from the
    high-level buffer, but the parser requests the source regions from
@@ -858,7 +858,7 @@ and scan_utf8 thread state = parse
    distinguish the first call to the function [scan], as the first
    scanning rule is actually [init] (which can handle the BOM), not
    [scan].
-*)
+ *)
 
 type logger = Markup.t list -> token -> unit
 
@@ -952,7 +952,7 @@ let open_token_stream input =
             in fail region Missing_break
       | _ -> () in
 
-  let rec read_token ~log buffer =
+  let rec read ~log buffer =
     match FQueue.deq !state.units with
       None ->
         scan buffer;