diff --git a/akka-statsd-core/src/main/scala/Config.scala b/akka-statsd-core/src/main/scala/Config.scala
index 9dd9ace..df78047 100644
--- a/akka-statsd-core/src/main/scala/Config.scala
+++ b/akka-statsd-core/src/main/scala/Config.scala
@@ -35,7 +35,7 @@ object Config {
         FiniteDuration(cfg.getDuration("transmit-interval", java.util.concurrent.TimeUnit.MILLISECONDS), MILLISECONDS),
       enableMultiMetric = cfg.getBoolean("enable-multi-metric"),
       emptyQueueOnFlush = cfg.getBoolean("empty-queue-on-flush"),
-      transformations = cfg.getConfigList("transformations").asScala.map(transformation),
+      transformations = cfg.getConfigList("transformations").asScala.toSeq.map(transformation),
       transformUuid = cfg.getBoolean("transform-uuid"),
       connectedUdp = cfg.getBoolean("connected-udp")
     )
diff --git a/akka-statsd-core/src/main/scala/transport/MultiMetricQueue.scala b/akka-statsd-core/src/main/scala/transport/MultiMetricQueue.scala
index 5bfe928..e2803f9 100644
--- a/akka-statsd-core/src/main/scala/transport/MultiMetricQueue.scala
+++ b/akka-statsd-core/src/main/scala/transport/MultiMetricQueue.scala
@@ -88,7 +88,7 @@ private[statsd] class MultiMetricQueue(val packetSize: Int)(implicit system: Act
   def flushQueue(): Stream[String] = Stream.continually(payload()).takeWhile(_.nonEmpty).flatten
 
   private object DroppedMessageWarning extends ((Int, String) => Unit) {
-    def apply(proposedAddition: Int, message: String) {
+    def apply(proposedAddition: Int, message: String): Unit = {
       if (!logger.isWarningEnabled)
         return
 
diff --git a/akka-statsd-core/src/main/scala/transport/ScheduledDispatcher.scala b/akka-statsd-core/src/main/scala/transport/ScheduledDispatcher.scala
index 89b1f52..11f0bf1 100644
--- a/akka-statsd-core/src/main/scala/transport/ScheduledDispatcher.scala
+++ b/akka-statsd-core/src/main/scala/transport/ScheduledDispatcher.scala
@@ -48,7 +48,7 @@ private[statsd] class ScheduledDispatcher(
       else mmq.payload().foreach(connection ! _)
   }
 
-  override def postStop() {
+  override def postStop(): Unit = {
     val _ = recurringTransmit.cancel()
   }
 
diff --git a/akka-statsd-core/src/main/scala/transport/UdpUnconnected.scala b/akka-statsd-core/src/main/scala/transport/UdpUnconnected.scala
index 460c9c5..27ad2b7 100644
--- a/akka-statsd-core/src/main/scala/transport/UdpUnconnected.scala
+++ b/akka-statsd-core/src/main/scala/transport/UdpUnconnected.scala
@@ -17,7 +17,7 @@ private[statsd] class UdpUnconnected(remoteAddress: InetSocketAddress) extends A
   def receive: Receive = waitingForConnection
 
   def waitingForConnection: Receive = {
-    case Udp.SimpleSenderReady ⇒
+    case Udp.SimpleSenderReady =>
       unstashAll()
       context become operational(sender())
     case _: String =>
diff --git a/akka-statsd-core/src/test/scala/StatsSpec.scala b/akka-statsd-core/src/test/scala/StatsSpec.scala
index a65d449..f3b6b8a 100644
--- a/akka-statsd-core/src/test/scala/StatsSpec.scala
+++ b/akka-statsd-core/src/test/scala/StatsSpec.scala
@@ -95,7 +95,7 @@ class StatsSpec
       .copy(address = boundListenerAddress())
     val statsProps = Stats.props(baseConfig)
 
-    def shutdown() {
+    def shutdown(): Unit = {
       listener ! Udp.Unbind
     }
   }
diff --git a/akka-statsd-core/src/test/scala/TestKit.scala b/akka-statsd-core/src/test/scala/TestKit.scala
index dfcf00f..09ab84b 100644
--- a/akka-statsd-core/src/test/scala/TestKit.scala
+++ b/akka-statsd-core/src/test/scala/TestKit.scala
@@ -9,7 +9,7 @@ trait BeforeAndAfterAllTestKit
 
   implicit def system: ActorSystem
 
-  override protected def afterAll() {
+  override protected def afterAll(): Unit = {
     akka.testkit.TestKit.shutdownActorSystem(system)
   }
 
diff --git a/akka-statsd-http-server/src/main/scala/StatsDirectives.scala b/akka-statsd-http-server/src/main/scala/StatsDirectives.scala
index df8fec1..da74e23 100644
--- a/akka-statsd-http-server/src/main/scala/StatsDirectives.scala
+++ b/akka-statsd-http-server/src/main/scala/StatsDirectives.scala
@@ -79,7 +79,7 @@ trait StatsDirectives extends AroundDirectives with BasicDirectives {
 
   def countRequestInBucket(baseBucket: String): Directive0 = {
     extractStats.flatMap { stats =>
-      Directive { innerRouteBuilder ⇒ ctx ⇒
+      Directive { innerRouteBuilder => ctx =>
         val req = ctx.request
         stats ! Increment(requestBucket(req.method, req.uri.path, baseBucket))
         innerRouteBuilder(())(ctx)
@@ -94,7 +94,7 @@ trait StatsDirectives extends AroundDirectives with BasicDirectives {
 
   def countResponseInBucket(baseBucket: String): Directive0 = {
     extractStats.flatMap { stats =>
-      Directive { innerRouteBuilder ⇒ ctx ⇒
+      Directive { innerRouteBuilder => ctx =>
         import ctx.executionContext
 
         val req = ctx.request
diff --git a/build.sbt b/build.sbt
index 10901bc..b71594d 100644
--- a/build.sbt
+++ b/build.sbt
@@ -1,13 +1,14 @@
-import com.typesafe.sbt.pgp.PgpKeys
 import ReleaseTransformations._
+import tnm.ScalaVersion
 
 val commonSettings = Seq(
   organization := "com.newmotion",
   licenses := Seq("MIT" -> url("http://opensource.org/licenses/MIT")),
   homepage := Some(url("https://github.com/NewMotion/akka-statsd")),
+  crossScalaVersions := Seq(ScalaVersion.curr, ScalaVersion.prev, ScalaVersion.aged),
   libraryDependencies ++= Seq(
     akka("testkit"),
-    "org.scalatest" %% "scalatest" % "3.0.5"
+    "org.scalatest" %% "scalatest" % "3.0.8"
   ).map(_ % "test"),
   releasePublishArtifactsAction := PgpKeys.publishSigned.value,
   releaseProcess := Seq[ReleaseStep](
@@ -76,8 +77,8 @@ val `akka-statsd` =
 
 def akka(lib: String) = {
   val version = lib match {
-    case x if x.startsWith("http") => "10.1.5"
-    case _ => "2.5.18"
+    case x if x.startsWith("http") => "10.1.10"
+    case _ => "2.5.25"
   }
 
   "com.typesafe.akka" %% s"akka-$lib" % version
diff --git a/project/build.properties b/project/build.properties
index 7c58a83..8522443 100644
--- a/project/build.properties
+++ b/project/build.properties
@@ -1 +1 @@
-sbt.version=1.2.6
+sbt.version=1.3.2
diff --git a/project/plugins.sbt b/project/plugins.sbt
index af5c36d..0e6ea56 100644
--- a/project/plugins.sbt
+++ b/project/plugins.sbt
@@ -1,4 +1,4 @@
-resolvers += "TNM" at "http://nexus.thenewmotion.com/content/groups/public"
+resolvers += "TNM" at "https://nexus.thenewmotion.com/content/groups/public"
 
-addSbtPlugin("com.newmotion" % "sbt-build-seed" % "4.1.2")
-addSbtPlugin("com.jsuereth" % "sbt-pgp" % "1.1.1")
+addSbtPlugin("com.newmotion" % "sbt-build-seed" % "5.0.4")
+addSbtPlugin("com.jsuereth" % "sbt-pgp" % "2.0.0")