diff --git a/lib/json/decode.ex b/lib/json/decode.ex
index caeb2c2..8cc5169 100644
--- a/lib/json/decode.ex
+++ b/lib/json/decode.ex
@@ -38,7 +38,7 @@ defmodule JSON.Decode do
     end
   end
 
-  # consume_value: binary -> { nil | true | false | List | HashDict | binary, binary }
+  # consume_value: binary -> { nil | true | false | List | Map | binary, binary }
 
   defp consume_value([ ?n, ?u, ?l, ?l  | rest ]), do: { :ok, nil,   rest }
   defp consume_value([ ?t, ?r, ?u, ?e  | rest ]), do: { :ok, true,  rest }
@@ -98,7 +98,7 @@ defmodule JSON.Decode do
     consume_value_result = consume_value(after_key)
     case consume_value_result do
       {:ok, value, after_value} ->
-        acc  = HashDict.put(acc, key, value)
+        acc  = Map.put(acc, key, value)
         after_value = consume_whitespace(after_value)
         case after_value do
           [ ?, | after_comma ] ->
@@ -109,7 +109,7 @@ defmodule JSON.Decode do
     end
   end
 
-  defp consume_object_contents(json) when is_list(json), do: consume_object_contents(HashDict.new, json)
+  defp consume_object_contents(json) when is_list(json), do: consume_object_contents(Map.new, json)
 
   defp consume_object_contents(acc, [ ?" | rest]) do
     consume_object_key_result = consume_object_key(rest)
diff --git a/lib/json/encode.ex b/lib/json/encode.ex
index 8c50cf7..b199a65 100644
--- a/lib/json/encode.ex
+++ b/lib/json/encode.ex
@@ -154,6 +154,33 @@ defimpl JSON.Encode, for: Record do
   def typeof(_), do: :object
 end
 
+# Encodes maps into object
+# > {:ok, "{\"a\":1,\"b\":2}"} = JSON.encode(%{a: 1, b: 2})
+defimpl JSON.Encode, for: Map do
+
+  def to_json(map) do
+      {:ok, "{" <> :maps.fold( fn
+        (key, object, "") -> encode_pair(key, object)
+        (key, object, acc) -> acc <> "," <> encode_pair(key, object)
+      end, "", map) <> "}"}
+  end
+
+  defp encode_pair(key, object) do
+    encode_item(key) <> ":" <>  encode_item(object)
+  end
+
+  defp encode_item(item) do
+    encode_result = JSON.Encode.to_json(item)
+    case encode_result do
+      {:ok, encoded_item} -> encoded_item
+      _ -> encode_result #propagate error, will trigger error in map_join
+    end
+  end
+
+  def typeof(_), do: :object
+end
+
+
 #TODO: maybe this should return the result of "inspect" ?
 defimpl JSON.Encode, for: Any do
   @any_to_json "[Elixir.Any]"
diff --git a/test/json_decode_test.exs b/test/json_decode_test.exs
index f13d5a1..041b0c6 100644
--- a/test/json_decode_test.exs
+++ b/test/json_decode_test.exs
@@ -54,9 +54,9 @@ defmodule JSONDecodeTest do
     decodes "float with positive exponent", "-1.22783E+4", -12278.3
     decodes "float with negative exponent", "903.4e-6", 0.0009034
 
-    decodes "empty object", "{}", HashDict.new
+    decodes "empty object", "{}", map.new
     decodes "simple object", "{\"result\": \"this is awesome\"}",\
-                  HashDict.new([ { "result", "this is awesome" } ])
+                  Map.new([ { "result", "this is awesome" } ])
 
     decodes "empty array", "  [   ] ", []
     decodes "simple array", "[ 1, 2, \"three\", 4 ]", [ 1, 2, "three", 4 ]
@@ -74,14 +74,14 @@ defmodule JSONDecodeTest do
                 { \"name\": \"Éloise\" }
               ]
              }",
-             HashDict.new([
+             Map.new([
               { "name", "Rafaëlla" },
               { "active", true },
               { "phone", "1.415.555.0000" },
               { "balance", 1.52e+5 },
               { "children", [
-                HashDict.new([ { "name", "Søren" } ]),
-                HashDict.new([ { "name", "Éloise" } ])
+                Map.new([ { "name", "Søren" } ]),
+                Map.new([ { "name", "Éloise" } ])
               ] }
             ])
 
diff --git a/test/json_encode_test.exs b/test/json_encode_test.exs
index aab6d84..ef5be76 100644
--- a/test/json_encode_test.exs
+++ b/test/json_encode_test.exs
@@ -42,4 +42,11 @@ defmodule JSONEncodeTest do
     assert \
       JSON.encode([result: "\\n"]) == {:ok, "{\"result\":\"\\\\n\"}"}
   end
+
+  test "convert maps into correct JSON" do
+    assert \
+      JSON.encode(%{a: 1, b: %{b1: 21}}) \
+      == {:ok, "{\"a\":1,\"b\":{\"b1\":21}}"}
+  end
+
 end