diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1aa8a44..704d502 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## v0.3.0 (2016-03-24)
+
+* Updated to sangria-marshalling-api v0.2.0
+
 ## v0.2.1 (2016-03-17)
 
 * Updated play-json to v2.5.0
diff --git a/README.md b/README.md
index ebf7cc1..c6e6c5d 100644
--- a/README.md
+++ b/README.md
@@ -5,7 +5,7 @@
 SBT Configuration:
 
 ```scala
-libraryDependencies += "org.sangria-graphql" %% "sangria-play-json" % "0.2.1"
+libraryDependencies += "org.sangria-graphql" %% "sangria-play-json" % "0.3.0"
 ```
 
 ## License
diff --git a/build.sbt b/build.sbt
index 6b20841..05f2fe7 100644
--- a/build.sbt
+++ b/build.sbt
@@ -1,6 +1,6 @@
 name := "sangria-play-json"
 organization := "org.sangria-graphql"
-version := "0.2.2-SNAPSHOT"
+version := "0.3.0"
 
 description := "Sangria play-json marshalling"
 homepage := Some(url("http://sangria-graphql.org"))
@@ -10,10 +10,10 @@ scalaVersion := "2.11.8"
 scalacOptions ++= Seq("-deprecation", "-feature")
 
 libraryDependencies ++= Seq(
-  "org.sangria-graphql" %% "sangria-marshalling-api" % "0.1.1",
+  "org.sangria-graphql" %% "sangria-marshalling-api" % "0.2.0",
   "com.typesafe.play" %% "play-json" % "2.5.0",
 
-  "org.sangria-graphql" %% "sangria-marshalling-testkit" % "0.1.2" % "test",
+  "org.sangria-graphql" %% "sangria-marshalling-testkit" % "0.2.0" % "test",
   "org.scalatest" %% "scalatest" % "2.2.6" % "test"
 )
 
diff --git a/src/main/scala/sangria/marshalling/playJson.scala b/src/main/scala/sangria/marshalling/playJson.scala
index 0b48663..6996e03 100644
--- a/src/main/scala/sangria/marshalling/playJson.scala
+++ b/src/main/scala/sangria/marshalling/playJson.scala
@@ -7,11 +7,13 @@ import scala.util.Try
 object playJson extends PlayJsonSupportLowPrioImplicits {
   implicit object PlayJsonResultMarshaller extends ResultMarshaller {
     type Node = JsValue
+    type MapBuilder = ArrayMapBuilder[Node]
 
-    def emptyMapNode = JsObject(Seq.empty)
+    def emptyMapNode(keys: Seq[String]) = new ArrayMapBuilder[Node](keys)
+    def addMapNodeElem(builder: MapBuilder, key: String, value: Node, optional: Boolean) = builder.add(key, value)
+
+    def mapNode(builder: MapBuilder) = JsObject(builder.toSeq)
     def mapNode(keyValues: Seq[(String, JsValue)]) = JsObject(keyValues)
-    def addMapNodeElem(node: JsValue, key: String, value: JsValue, optional: Boolean) =
-      node.asInstanceOf[JsObject] + (key → value)
 
     def arrayNode(values: Vector[JsValue]) = JsArray(values)