diff --git a/project/Build.scala b/project/Build.scala
index 3885d6b..ef04c47 100644
--- a/project/Build.scala
+++ b/project/Build.scala
@@ -1,9 +1,4 @@
 import sbt._, Keys._
-import sbtrelease._
-import sbtrelease.ReleasePlugin.autoImport._
-import xerial.sbt.Sonatype._
-import ReleaseStateTransformations._
-import com.typesafe.sbt.pgp.PgpKeys
 
 object build extends Build {
 
@@ -16,7 +11,6 @@ object build extends Build {
   val modules = msgpack4zJava07Name :: Nil
 
   lazy val msgpack4zJava07 = Project("msgpack4z-java07", file(".")).settings(
-    ReleasePlugin.extraReleaseCommands ++ sonatypeSettings: _*
   ).settings(
     resolvers += Opts.resolver.sonatypeReleases,
     fullResolvers ~= {_.filterNot(_.name == "jcenter")},
@@ -25,30 +19,10 @@ object build extends Build {
     name := msgpack4zJava07Name,
     javacOptions in compile ++= Seq("-target", "6", "-source", "6"),
     javacOptions in (Compile, doc) ++= Seq("-locale", "en_US"),
-    commands += Command.command("updateReadme")(UpdateReadme.updateReadmeTask),
     libraryDependencies ++= (
-      ("org.msgpack" % "msgpack-core" % "0.7.1") ::
       ("com.github.xuwei-k" % "msgpack4z-api" % "0.2.0") ::
       Nil
     ),
-    releaseProcess := Seq[ReleaseStep](
-      checkSnapshotDependencies,
-      inquireVersions,
-      runClean,
-      runTest,
-      setReleaseVersion,
-      commitReleaseVersion,
-      UpdateReadme.updateReadmeProcess,
-      tagRelease,
-      ReleaseStep(state => Project.extract(state).runTask(PgpKeys.publishSigned, state)._1),
-      setNextVersion,
-      commitNextVersion,
-      UpdateReadme.updateReadmeProcess,
-      ReleaseStep(state =>
-        Project.extract(state).runTask(SonatypeKeys.sonatypeReleaseAll, state)._1
-      ),
-      pushChanges
-    ),
     credentials ++= PartialFunction.condOpt(sys.env.get("SONATYPE_USER") -> sys.env.get("SONATYPE_PASS")){
       case (Some(user), Some(pass)) =>
         Credentials("Sonatype Nexus Repository Manager", "oss.sonatype.org", user, pass)
@@ -82,6 +56,8 @@ object build extends Build {
       </scm>
     ,
     description := "msgpack4z"
+  ).dependsOn(
+    ProjectRef(uri("git://github.com/msgpack/msgpack-java.git#97e9599db0eace27a8191f321d619e224712235b"), "msgpack-core")
   )
 
 }
diff --git a/project/UpdateReadme.scala b/project/UpdateReadme.scala
deleted file mode 100644
index 90cad28..0000000
--- a/project/UpdateReadme.scala
+++ /dev/null
@@ -1,34 +0,0 @@
-import sbt._, Keys._
-import sbtrelease.ReleasePlugin.autoImport.ReleaseStep
-import sbtrelease.Git
-
-object UpdateReadme {
-
-  private val sonatypeURL = "https://oss.sonatype.org/service/local/repositories/"
-
-  lazy val updateReadmeProcess: ReleaseStep = updateReadmeTask
-
-  val updateReadmeTask = { state: State =>
-    val extracted = Project.extract(state)
-    val v = extracted get version
-    val org =  extracted get organization
-    val modules = build.modules
-    val snapshotOrRelease = if(extracted get isSnapshot) "snapshots" else "releases"
-    val readme = "README.md"
-    val readmeFile = file(readme)
-    val newReadme = Predef.augmentString(IO.read(readmeFile)).lines.map{ line =>
-      val matchReleaseOrSnapshot = line.contains("SNAPSHOT") == v.contains("SNAPSHOT")
-      if(line.startsWith("libraryDependencies") && matchReleaseOrSnapshot){
-        val i = modules.indexWhere(line.contains)
-        s"""libraryDependencies += "${org}" % "${modules(i)}" % "$v""""
-      }else line
-    }.mkString("", "\n", "\n")
-    IO.write(readmeFile, newReadme)
-    val git = new Git(extracted get baseDirectory)
-    git.add(readme) ! state.log
-    git.commit("update " + readme) ! state.log
-    "git diff HEAD^" ! state.log
-    state
-  }
-
-}
diff --git a/project/plugin.sbt b/project/plugin.sbt
index 6f24891..15d7c1b 100644
--- a/project/plugin.sbt
+++ b/project/plugin.sbt
@@ -1,6 +1,3 @@
-addSbtPlugin("com.jsuereth" % "sbt-pgp" % "1.0.0")
-addSbtPlugin("com.github.gseitz" % "sbt-release" % "1.0.1")
-addSbtPlugin("org.xerial.sbt" % "sbt-sonatype" % "0.4.0")
 
 scalacOptions ++= (
   "-deprecation" ::