diff --git a/src/Pure/General/bytes.ML b/src/Pure/General/bytes.ML
deleted file mode 100644
--- a/src/Pure/General/bytes.ML
+++ /dev/null
@@ -1,31 +0,0 @@
-(*  Title:      Pure/General/bytes.ML
-    Author:     Makarius
-
-Byte-vector messages.
-*)
-
-signature BYTES =
-sig
-  val read_line: BinIO.instream -> string option
-  val read_block: BinIO.instream -> int -> string
-end;
-
-structure Bytes: BYTES =
-struct
-
-fun read_line stream =
-  let
-    val result = trim_line o String.implode o rev;
-    fun read cs =
-      (case BinIO.input1 stream of
-        NONE => if null cs then NONE else SOME (result cs)
-      | SOME b =>
-          (case Byte.byteToChar b of
-            #"\n" => SOME (result cs)
-          | c => read (c :: cs)));
-  in read [] end;
-
-fun read_block stream n =
-  Byte.bytesToString (BinIO.inputN (stream, n));
-
-end;