diff --git a/src/frontend/lexer.mll b/src/frontend/lexer.mll
index 821a7f3b0..d8a08948e 100644
--- a/src/frontend/lexer.mll
+++ b/src/frontend/lexer.mll
@@ -554,8 +554,8 @@ and mathexpr stack = parse
   | "^" { SUPERSCRIPT(get_pos lexbuf) }
   | "_" { SUBSCRIPT(get_pos lexbuf) }
   | "'"+ { let n = String.length (Lexing.lexeme lexbuf) in PRIMES(get_pos lexbuf, n) }
-  | (mathsymboltop (mathsymbol*)) { MATHCHAR(get_pos lexbuf, Lexing.lexeme lexbuf) }
-  | mathstr+ { MATHCHAR(get_pos lexbuf, Lexing.lexeme lexbuf) }
+  | (mathsymboltop (mathsymbol*)) { MATHCHARS(get_pos lexbuf, Lexing.lexeme lexbuf) }
+  | mathstr+ { MATHCHARS(get_pos lexbuf, Lexing.lexeme lexbuf) }
   | ("#" (identifier as varnm)) {
       VARINMATH(get_pos lexbuf, [], varnm)
     }
@@ -577,7 +577,7 @@ and mathexpr stack = parse
     }
   | ("\\" symbol) {
       let tok = String.sub (Lexing.lexeme lexbuf) 1 1 in
-        MATHCHAR(get_pos lexbuf, tok)
+        MATHCHARS(get_pos lexbuf, tok)
     }
   | _ as c { report_error lexbuf ("illegal token '" ^ (String.make 1 c) ^ "' in a math area") }
 
diff --git a/src/frontend/parser.mly b/src/frontend/parser.mly
index a513182ed..71082912b 100644
--- a/src/frontend/parser.mly
+++ b/src/frontend/parser.mly
@@ -383,7 +383,7 @@
 %token <Range.t * string * bool * bool> LITERAL
 %token <Range.t * Types.input_position * string> POSITIONED_LITERAL
 %token <Range.t> SPACE BREAK
-%token <Range.t * string> MATHCHAR
+%token <Range.t * string> MATHCHARS
 %token <Range.t * int> PRIMES
 %token <Range.t> SUBSCRIPT SUPERSCRIPT
 %token <Range.t> LAMBDA ARROW COMMAND
@@ -1120,7 +1120,9 @@ mathgroup:
   | utm=mathbot                              { utm }
 ;
 mathbot:
-  | tok=MATHCHAR                    { let (rng, char) = tok in (rng, UTMChar(char)) }
+  | tok=MATHCHARS {
+      let (rng, s) = tok in (rng, UTMChar(s))
+    }
   | mcmd=mcmd; arglst=list(matharg) {
       let (rngcmd, mdlnmlst, csnm) = mcmd in
       let rnglast =