diff --git a/json_serialization/lexer.nim b/json_serialization/lexer.nim
index 53ae219..f8cd957 100644
--- a/json_serialization/lexer.nim
+++ b/json_serialization/lexer.nim
@@ -41,7 +41,7 @@ type
     errNonPortableInt       = "number is outside the range of portable values"
 
   JsonLexer* = object
-    stream: AsciiInputStream
+    stream: InputStream
     mode*: JsonMode
 
     line*: int
@@ -61,6 +61,12 @@ const
                  1e20, 1e21, 1e22] # TODO: this table should be much larger
                                    # The largest JSON number value is 1E308
 
+template peek(s: InputStream): char =
+  char input_stream.peek(s)
+
+template read(s: InputStream): char =
+  char input_stream.read(s)
+
 proc hexCharValue(c: char): int {.inline.} =
   case c
   of '0'..'9': ord(c) - ord('0')
@@ -77,7 +83,7 @@ proc col*(lexer: JsonLexer): int =
 proc tokenStartCol*(lexer: JsonLexer): int =
   1 + lexer.tokenStart - lexer.lineStartPos
 
-proc init*(T: type JsonLexer, stream: AsciiInputStream, mode = defaultJsonMode): T =
+proc init*(T: type JsonLexer, stream: InputStream, mode = defaultJsonMode): T =
   T(stream: stream,
     mode: mode,
     line: 1,
@@ -89,9 +95,6 @@ proc init*(T: type JsonLexer, stream: AsciiInputStream, mode = defaultJsonMode):
     floatVal: 0'f,
     strVal: "")
 
-proc init*(T: type JsonLexer, stream: InputStream, mode = defaultJsonMode): T =
-  init(JsonLexer, AsciiInputStream(stream), mode)
-
 template error(error: JsonErrorKind) {.dirty.} =
   lexer.err = error
   lexer.tok = tkError
diff --git a/json_serialization/reader.nim b/json_serialization/reader.nim
index 4e804c4..0c51086 100644
--- a/json_serialization/reader.nim
+++ b/json_serialization/reader.nim
@@ -61,9 +61,6 @@ method formatMsg*(err: ref GenericJsonReaderError, filename: string): string =
 method formatMsg*(err: ref IntOverflowError, filename: string): string =
   fmt"{filename}({err.line}, {err.col}) The value '{err.valueStr}' is outside of the allowed range"
 
-template init*(T: type JsonReader, stream: InputStream, mode = defaultJsonMode): auto =
-  init JsonReader, AsciiInputStream(stream), mode
-
 proc assignLineNumber*(ex: ref JsonReaderError, r: JsonReader) =
   ex.line = r.lexer.line
   ex.col = r.lexer.tokenStartCol
@@ -100,7 +97,7 @@ proc handleReadException*(r: JsonReader,
   ex.innerException = err
   raise ex
 
-proc init*(T: type JsonReader, stream: AsciiInputStream, mode = defaultJsonMode): T =
+proc init*(T: type JsonReader, stream: InputStream, mode = defaultJsonMode): T =
   result.lexer = JsonLexer.init(stream, mode)
   result.lexer.next()