diff --git a/.gitignore b/.gitignore
index c68b95d..3c0dbb6 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,3 +5,4 @@ package-lock.json
 nimble.develop
 nimble.paths
 vendor
+tests/test_all
diff --git a/toml_serialization.nim b/toml_serialization.nim
index 3f7bbc1..f2643bb 100644
--- a/toml_serialization.nim
+++ b/toml_serialization.nim
@@ -91,7 +91,7 @@ template tomlDecodeImpl*(input: untyped,
     # from the fact that the dynamic dispatch mechanisms used in
     # faststreams may be reading from a file or a network device.
     try:
-      let stream = memInputStream(input)
+      let stream = unsafeMemoryInput(input)
       var reader = unpackArgs(init, [TomlReader, stream, tomlCase, params])
       when RecordType is (seq or array) and uTypeIsRecord(RecordType):
         reader.readTableArray(RecordType, key, tomlCase)
@@ -143,7 +143,7 @@ template tomlLoadImpl*(filename: string,
   var stream: InputStream
   when nimvm:
     let input = staticRead(filename)
-    stream = VMInputStream(pos: 0, data: toVMString(input))
+    stream = unsafeMemoryInput(input)
   else:
     stream = memFileInput(filename)
   try:
diff --git a/toml_serialization.nimble b/toml_serialization.nimble
index 333a8c6..7d9c458 100644
--- a/toml_serialization.nimble
+++ b/toml_serialization.nimble
@@ -8,6 +8,7 @@ license       = "Apache License 2.0"
 skipDirs      = @["tests", "assets"]
 
 requires "nim >= 1.6.0",
+         "faststreams >= 0.5.0",
          "serialization",
          "stew"
 
diff --git a/toml_serialization/lexer.nim b/toml_serialization/lexer.nim
index 47f46bc..9c337ef 100644
--- a/toml_serialization/lexer.nim
+++ b/toml_serialization/lexer.nim
@@ -66,22 +66,13 @@ const
   invalidCommentChar = {'\x00'..'\x08', '\x0A'..'\x1F', '\x7F'}
 
 template readChar*(lex: TomlLexer): char =
-  when nimvm:
-    read(VMInputStream(lex.stream))
-  else:
-    char inputs.read(lex.stream)
+  char inputs.read(lex.stream)
 
 template readable*(lex: TomlLexer): bool =
-  when nimvm:
-    readable(VMInputStream(lex.stream))
-  else:
-    lex.stream.readable()
+  lex.stream.readable()
 
 template peekChar*(lex: TomlLexer): char =
-  when nimvm:
-    peekChar(VMInputStream(lex.stream))
-  else:
-    lex.stream.peek().char
+  lex.stream.peek().char
 
 proc lineInfo(lex: TomlLexer): (int, int) {.inline.} =
   (lex.line, lex.col)
@@ -1930,7 +1921,7 @@ proc parseKeyValue*(lex: var TomlLexer,
   checkEol(lex, line)
 
 proc parseKey*(key: string, tomlCase: TomlCase): seq[string] =
-  let stream = memInputStream(key)
+  let stream = unsafeMemoryInput(key)
   var lex = init(TomlLexer, stream)
   lex.scanKey(result)
 
diff --git a/toml_serialization/types.nim b/toml_serialization/types.nim
index 5c22476..8cfae16 100644
--- a/toml_serialization/types.nim
+++ b/toml_serialization/types.nim
@@ -245,33 +245,13 @@ proc toUgly(result: var string, p: TomlValueRef) =
 proc `$`*(p: TomlValueRef): string =
   toUgly(result, p)
 
-type
-  VMInputStream* = ref object of InputStream
-    pos*: int
-    data*: string
-
-proc read*(s: VMInputStream): char =
-  result = s.data[s.pos]
-  inc s.pos
-
-proc readable*(s: VMInputStream): bool =
-  s.pos < s.data.len
-
-proc peekChar*(s: VMInputStream): char =
-  s.data[s.pos]
-
-template toVMString*(x: openArray[byte]): string =
+template toVMString*(x: openArray[byte]): string {.deprecated.} =
   var z = newString(x.len)
   for i, c in x: z[i] = char(c)
   z
 
-template toVMString*(x: string): string =
+template toVMString*(x: string): string {.deprecated.} =
   x
 
-template memInputStream*(input: untyped): auto =
-  var stream: InputStream
-  when nimvm:
-    stream = VMInputStream(pos: 0, data: toVMString(input))
-  else:
-    stream = unsafeMemoryInput(input)
-  stream
+template memInputStream*(input: untyped): auto {.deprecated: "use unsafeMemoryInput".} =
+  unsafeMemoryInput(input)