diff --git a/src/ast/text.ml b/src/ast/text.ml
index 715058535..d43be566d 100644
--- a/src/ast/text.ml
+++ b/src/ast/text.ml
@@ -38,7 +38,7 @@ type data =
   }
 
 let pp_data fmt (d : data) =
-  pf fmt {|(data%a %a %S)|} pp_id_opt d.id pp_data_mode d.mode d.init
+  pf fmt {|(data%a %a %a)|} pp_id_opt d.id pp_data_mode d.mode pp_name d.init
 
 type elem_mode =
   | Elem_passive
diff --git a/src/ast/types.ml b/src/ast/types.ml
index ea06dc3c2..28b723801 100644
--- a/src/ast/types.ml
+++ b/src/ast/types.ml
@@ -36,6 +36,28 @@ type _ indice =
 
 let pp_id fmt id = pf fmt "$%s" id
 
+let pp_name_inner fmt s =
+  let pp_hex_char fmt c = pf fmt "\\%02x" (Char.code c) in
+  let pp_char fmt = function
+    | '\n' -> string fmt "\\n"
+    | '\r' -> string fmt "\\r"
+    | '\t' -> string fmt "\\t"
+    | '\'' -> string fmt "\\'"
+    | '\"' -> string fmt "\\\""
+    | '\\' -> string fmt "\\\\"
+    | c ->
+      let ci = Char.code c in
+      if 0x20 <= ci && ci < 0x7f then char fmt c else pp_hex_char fmt c
+  in
+  let pp_unicode_char fmt = function
+    | (0x09 | 0x0a) as c -> pp_char fmt (Char.chr c)
+    | uc when 0x20 <= uc && uc < 0x7f -> pp_char fmt (Char.chr uc)
+    | uc -> pf fmt "\\u{%02x}" uc
+  in
+  String.iter (fun c -> pp_unicode_char fmt (Char.code c)) s
+
+let pp_name fmt s = pf fmt {|"%a"|} pp_name_inner s
+
 let pp_id_opt fmt = function None -> () | Some i -> pf fmt " %a" pp_id i
 
 let pp_indice (type kind) fmt : kind indice -> unit = function
diff --git a/src/parser/text_lexer.ml b/src/parser/text_lexer.ml
index 737c36b6b..50f517658 100644
--- a/src/parser/text_lexer.ml
+++ b/src/parser/text_lexer.ml
@@ -49,7 +49,7 @@ let mk_string buf s =
         | 't' -> '\t'
         | '\\' -> '\\'
         | '\'' -> '\''
-        | '\"' -> '\"'
+        | '"' -> '"'
         | 'u' ->
           let j = !i + 2 in
           begin
@@ -103,13 +103,13 @@ let frac = [%sedlex.regexp? num]
 
 let float =
   [%sedlex.regexp?
-    ( Opt sign, num, '.', Opt frac
-    | Opt sign, num, Opt ('.', Opt frac), ('e' | 'E'), Opt sign, num
-    | Opt sign, "0x", hexnum, '.', Opt hexfrac
-    | Opt sign, "0x", hexnum, Opt ('.', Opt hexfrac), ('p' | 'P'), Opt sign, num
-    | Opt sign, "inf"
-    | Opt sign, "nan"
-    | Opt sign, "nan:", "0x", hexnum )]
+      ( Opt sign, num, '.', Opt frac
+      | Opt sign, num, Opt ('.', Opt frac), ('e' | 'E'), Opt sign, num
+      | Opt sign, "0x", hexnum, '.', Opt hexfrac
+      | Opt sign, "0x", hexnum, Opt ('.', Opt hexfrac), ('p' | 'P'), Opt sign, num
+      | Opt sign, "inf"
+      | Opt sign, "nan"
+      | Opt sign, "nan:", "0x", hexnum )]
 
 let nat = [%sedlex.regexp? num | "0x", hexnum]
 
@@ -119,15 +119,38 @@ let num = [%sedlex.regexp? float | int | nat]
 
 let id_char =
   [%sedlex.regexp?
-    ( '0' .. '9'
-    | 'a' .. 'z'
-    | 'A' .. 'Z'
-    | '!' | '#' | '$' | '%' | '&' | '\'' | '*' | '+' | '-' | '.' | '/' | ':'
-    | '<' | '=' | '>' | '?' | '@' | '\\' | '^' | '_' | '`' | '|' | '~' )]
+      ( '0' .. '9'
+      | 'a' .. 'z'
+      | 'A' .. 'Z'
+      | '!' | '#' | '$' | '%' | '&' | '\'' | '*' | '+' | '-' | '.' | '/' | ':'
+      | '<' | '=' | '>' | '?' | '@' | '\\' | '^' | '_' | '`' | '|' | '~' )]
 
 let string_elem = [%sedlex.regexp? Sub (any, "\"") | "\\\""]
 
-let name = [%sedlex.regexp? "\"", Star string_elem, "\""]
+let utf8cont = [%sedlex.regexp? '\x80' .. '\xbf']
+
+let utf8enc =
+  [%sedlex.regexp?
+      ( '\xc2' .. '\xdf', utf8cont
+      | '\xe0', '\xa0' .. '\xbf', utf8cont
+      | '\xed', '\x80' .. '\x9f', utf8cont
+      | ('\xe1' .. '\xec' | '\xee' .. '\xef'), utf8cont, utf8cont
+      | '\xf0', '\x90' .. '\xbf', utf8cont, utf8cont
+      | '\xf4', '\x80' .. '\x8f', utf8cont, utf8cont
+      | '\xf1' .. '\xf3', utf8cont, utf8cont, utf8cont )]
+
+let escape = [%sedlex.regexp? 'n' | 'r' | 't' | '\\' | '\'' | '"']
+
+let character =
+  [%sedlex.regexp?
+      ( Sub (any, ('"' | '\\' | '\x00' .. '\x1f' | '\x7f' .. '\xff'))
+      | utf8enc
+      | '\\', escape
+      | '\\', hexdigit, hexdigit
+      | '\\', "u{", hexnum, '}' )]
+
+(* TODO: use character here instead of string_elem ? *)
+let name = [%sedlex.regexp? '"', Star string_elem, '"']
 
 let operator =
   [%sedlex.regexp? Plus ('0' .. '9' | 'a' .. 'z' | '.' | '_' | ':'), Star name]
@@ -142,7 +165,7 @@ let bad_num = [%sedlex.regexp? num, Plus id]
 
 let annot_atom =
   [%sedlex.regexp?
-    Plus id_char | num | name | ',' | ';' | '[' | ']' | '{' | '}']
+      Plus id_char | num | name | ',' | ';' | '[' | ']' | '{' | '}']
 
 let keywords =
   let tbl = Hashtbl.create 512 in
@@ -449,33 +472,34 @@ let keywords =
   tbl
 
 let rec token buf =
+  (* Fmt.epr "LXM = %S@\n" (Utf8.lexeme buf); *)
   match%sedlex buf with
   | Plus any_blank -> token buf
   | bad_num | bad_id | bad_name -> unknown_operator buf
   | num -> NUM (Utf8.lexeme buf)
-  | operator -> begin
+  | operator ->
     let operator = Utf8.lexeme buf in
     match Hashtbl.find_opt keywords operator with
     | None -> unknown_operator buf
     | Some v -> v
-  end
-  (* comment *)
-  | ";;" ->
-    single_comment buf;
-    token buf
-  | "(;" ->
-    comment buf;
+end
+(* comment *)
+| ";;" ->
+  single_comment buf;
+  token buf
+| "(;" ->
+  comment buf;
+  token buf
+(* custom annotation *)
+| "(@", name ->
+  let annotid = Utf8.lexeme buf in
+  let annotid = String.sub annotid 3 (String.length annotid - 4) in
+  let annotid = mk_string buf annotid in
+  if String.equal "" annotid then raise Empty_annotation_id
+  else
+    let items = Sexp.List (annot buf) in
+    Annot.(record_annot annotid items);
     token buf
-  (* custom annotation *)
-  | "(@", name ->
-    let annotid = Utf8.lexeme buf in
-    let annotid = String.sub annotid 3 (String.length annotid - 4) in
-    let annotid = mk_string buf annotid in
-    if String.equal "" annotid then raise Empty_annotation_id
-    else
-      let items = Sexp.List (annot buf) in
-      Annot.(record_annot annotid items);
-      token buf
   | "(@", Plus id_char ->
     let annotid = Utf8.lexeme buf in
     let annotid = String.sub annotid 2 (String.length annotid - 2) in
@@ -501,7 +525,6 @@ let rec token buf =
     NAME name
   | "\"", Star string_elem -> raise Unclosed_string
   | eof -> EOF
-  (* | "" -> EOF *)
   | any -> unknown_operator buf
   | _ -> unknown_operator buf
 
diff --git a/src/script/script.ml b/src/script/script.ml
index 58b7ad577..cae1fb204 100644
--- a/src/script/script.ml
+++ b/src/script/script.ml
@@ -198,8 +198,8 @@ let run ~no_exhaustion ~optimize script =
         link_state
       | Assert (Assert_malformed_quote (m, expected)) ->
         Log.debug0 "*** assert_malformed_quote@\n";
-        (* TODO: use Parse.Text.Module.from_string instead *)
-        let got = Parse.Text.Script.from_string m in
+        let m = Fmt.str "%a" pp_name_inner m in
+        let got = Parse.Text.Module.from_string m in
         let+ () =
           match got with
           | Error got -> check_error ~expected ~got
@@ -208,7 +208,6 @@ let run ~no_exhaustion ~optimize script =
               Compile.Text.until_binary ~unsafe ~rac:false ~srac:false m
             in
             check_error_result expected got
-          | _ -> assert false
         in
         link_state
       | Assert (Assert_invalid_binary (m, expected)) ->
diff --git a/test/fmt/data.wat b/test/fmt/data.wat
new file mode 100644
index 000000000..b00d322e7
--- /dev/null
+++ b/test/fmt/data.wat
@@ -0,0 +1,4 @@
+(module
+  (memory $m 1)
+  (data $d (i32.const 0) "hello" "\n" "\\n" "\\" "\\'" "\'" "\\r" "\r" "\\t" "\t" "\\\"" "\"" "world" "!")
+)
diff --git a/test/fmt/dune b/test/fmt/dune
index 8c5d72d10..c159d6f22 100644
--- a/test/fmt/dune
+++ b/test/fmt/dune
@@ -7,6 +7,7 @@
  (deps
   %{bin:owi}
   print_simplified.exe
+  data.wat
   done.wat
   m.wat
   locals.wat
diff --git a/test/fmt/print.t b/test/fmt/print.t
index 02315233c..baa543fdd 100644
--- a/test/fmt/print.t
+++ b/test/fmt/print.t
@@ -32,3 +32,9 @@ print simplified:
     )
     (start 1)
   )
+print data:
+  $ owi fmt data.wat
+  (module
+    (memory $m 1)
+    (data $d (memory 0) (offset i32.const 0) "hello\n\\n\\\\\'\'\\r\u{0d}\\t\t\\\"\"world!")
+  )
diff --git a/test/script/passing.t b/test/script/passing.t
index afa8785af..e5311683d 100644
--- a/test/script/passing.t
+++ b/test/script/passing.t
@@ -38,6 +38,8 @@
   $ owi script --no-exhaustion passing/quickstart.wast
   $ owi script --no-exhaustion passing/relop.wast
   $ owi script --no-exhaustion passing/stringinitmsg.wast
+  expected illegal escape but got (unknown operator unexpected character `"\""`)
+  [54]
   $ owi script --no-exhaustion passing/type_abbreviations.wast
   $ owi script --no-exhaustion passing/typecheck3.wast
   $ owi script --no-exhaustion passing/typecheck4.wast
diff --git a/test/script/reference.t b/test/script/reference.t
index 82fb02efb..80faf2b2c 100644
--- a/test/script/reference.t
+++ b/test/script/reference.t
@@ -74,8 +74,8 @@
   $ owi script --no-exhaustion reference/memory_trap.wast
   $ owi script --no-exhaustion reference/memory.wast
   $ owi script --no-exhaustion reference/names.wast
-  42
-  123
+  unknown operator unexpected character `"\""`
+  [23]
   $ owi script --no-exhaustion reference/nop.wast
   $ owi script --no-exhaustion reference/ref_func.wast
   $ owi script --no-exhaustion reference/ref_is_null.wast
diff --git a/test/script/reference_opt.t b/test/script/reference_opt.t
index bc1f0e6c1..38ee4af31 100644
--- a/test/script/reference_opt.t
+++ b/test/script/reference_opt.t
@@ -74,8 +74,8 @@
   $ owi script --no-exhaustion --optimize reference/memory_trap.wast
   $ owi script --no-exhaustion --optimize reference/memory.wast
   $ owi script --no-exhaustion --optimize reference/names.wast
-  42
-  123
+  unknown operator unexpected character `"\""`
+  [23]
   $ owi script --no-exhaustion --optimize reference/nop.wast
   $ owi script --no-exhaustion --optimize reference/ref_func.wast
   $ owi script --no-exhaustion --optimize reference/ref_is_null.wast