diff --git a/akka-actor-tests/src/test/scala/akka/actor/dispatch/ActorModelSpec.scala b/akka-actor-tests/src/test/scala/akka/actor/dispatch/ActorModelSpec.scala
index 5b7431d564..8761f48f34 100644
--- a/akka-actor-tests/src/test/scala/akka/actor/dispatch/ActorModelSpec.scala
+++ b/akka-actor-tests/src/test/scala/akka/actor/dispatch/ActorModelSpec.scala
@@ -22,6 +22,7 @@ import akka.pattern.ask
 import akka.testkit._
 import akka.util.{ Timeout, Switch, Duration }
 import akka.util.duration._
+import annotation.tailrec
 
 object ActorModelSpec {
 
@@ -224,16 +225,16 @@ object ActorModelSpec {
     }
   }
 
-  def await(until: Long)(condition: ⇒ Boolean): Unit = try {
-    while (System.currentTimeMillis() <= until) {
-      try {
-        if (condition) return else Thread.sleep(25)
-      } catch {
-        case e: InterruptedException ⇒
-      }
+  def await(until: Long)(condition: ⇒ Boolean): Unit = if (System.currentTimeMillis() <= until) {
+    var done = false
+    try {
+      done = condition
+      if (!done) Thread.sleep(25)
+    } catch {
+      case e: InterruptedException ⇒
     }
-    throw new AssertionError("await failed")
-  }
+    if (!done) await(until)(condition)
+  } else throw new AssertionError("await failed")
 }
 
 abstract class ActorModelSpec(config: String) extends AkkaSpec(config) with DefaultTimeout {
diff --git a/akka-actor-tests/src/test/scala/akka/performance/workbench/BenchResultRepository.scala b/akka-actor-tests/src/test/scala/akka/performance/workbench/BenchResultRepository.scala
index e0e6b0e1e2..1cccd19417 100644
--- a/akka-actor-tests/src/test/scala/akka/performance/workbench/BenchResultRepository.scala
+++ b/akka-actor-tests/src/test/scala/akka/performance/workbench/BenchResultRepository.scala
@@ -102,20 +102,21 @@ class FileBenchResultRepository extends BenchResultRepository {
 
   private def save(stats: Stats) {
     new File(serDir).mkdirs
-    if (!serDirExists) return
-    val timestamp = new SimpleDateFormat("yyyyMMddHHmmss").format(new Date(stats.timestamp))
-    val name = stats.name + "--" + timestamp + "--" + stats.load + ".ser"
-    val f = new File(serDir, name)
-    var out: ObjectOutputStream = null
-    try {
-      out = new ObjectOutputStream(new BufferedOutputStream(new FileOutputStream(f)))
-      out.writeObject(stats)
-    } catch {
-      case e: Exception ⇒
-        val errMsg = "Failed to save [%s] to [%s], due to [%s]".format(stats, f.getAbsolutePath, e.getMessage)
-        throw new RuntimeException(errMsg)
-    } finally {
-      if (out ne null) try { out.close() } catch { case ignore: Exception ⇒ }
+    if (serDirExists) {
+      val timestamp = new SimpleDateFormat("yyyyMMddHHmmss").format(new Date(stats.timestamp))
+      val name = stats.name + "--" + timestamp + "--" + stats.load + ".ser"
+      val f = new File(serDir, name)
+      var out: ObjectOutputStream = null
+      try {
+        out = new ObjectOutputStream(new BufferedOutputStream(new FileOutputStream(f)))
+        out.writeObject(stats)
+      } catch {
+        case e: Exception ⇒
+          val errMsg = "Failed to save [%s] to [%s], due to [%s]".format(stats, f.getAbsolutePath, e.getMessage)
+          throw new RuntimeException(errMsg)
+      } finally {
+        if (out ne null) try { out.close() } catch { case ignore: Exception ⇒ }
+      }
     }
   }
 
@@ -142,19 +143,20 @@ class FileBenchResultRepository extends BenchResultRepository {
 
   def saveHtmlReport(content: String, fileName: String) {
     new File(htmlDir).mkdirs
-    if (!htmlDirExists) return
-    val f = new File(htmlDir, fileName)
-    var writer: PrintWriter = null
-    try {
-      writer = new PrintWriter(new FileWriter(f))
-      writer.print(content)
-      writer.flush()
-    } catch {
-      case e: Exception ⇒
-        val errMsg = "Failed to save report to [%s], due to [%s]".format(f.getAbsolutePath, e.getMessage)
-        throw new RuntimeException(errMsg)
-    } finally {
-      if (writer ne null) try { writer.close() } catch { case ignore: Exception ⇒ }
+    if (htmlDirExists) {
+      val f = new File(htmlDir, fileName)
+      var writer: PrintWriter = null
+      try {
+        writer = new PrintWriter(new FileWriter(f))
+        writer.print(content)
+        writer.flush()
+      } catch {
+        case e: Exception ⇒
+          val errMsg = "Failed to save report to [%s], due to [%s]".format(f.getAbsolutePath, e.getMessage)
+          throw new RuntimeException(errMsg)
+      } finally {
+        if (writer ne null) try { writer.close() } catch { case ignore: Exception ⇒ }
+      }
     }
   }
 
diff --git a/akka-actor-tests/src/test/scala/akka/performance/workbench/GoogleChartBuilder.scala b/akka-actor-tests/src/test/scala/akka/performance/workbench/GoogleChartBuilder.scala
index c513200310..52b30ceee7 100644
--- a/akka-actor-tests/src/test/scala/akka/performance/workbench/GoogleChartBuilder.scala
+++ b/akka-actor-tests/src/test/scala/akka/performance/workbench/GoogleChartBuilder.scala
@@ -17,131 +17,133 @@ object GoogleChartBuilder {
    * Builds a bar chart for tps in the statistics.
    */
   def tpsChartUrl(statsByTimestamp: TreeMap[Long, Seq[Stats]], title: String, legend: Stats ⇒ String): String = {
-    if (statsByTimestamp.isEmpty) return ""
+    if (statsByTimestamp.isEmpty) ""
+    else {
+      val loads = statsByTimestamp.values.head.map(_.load)
+      val allStats = statsByTimestamp.values.flatten
 
-    val loads = statsByTimestamp.values.head.map(_.load)
-    val allStats = statsByTimestamp.values.flatten
+      val sb = new StringBuilder
+      sb.append(BaseUrl)
+      // bar chart
+      sb.append("cht=bvg")
+      sb.append("&")
+      // size
+      sb.append("chs=").append(ChartWidth).append("x").append(ChartHeight)
+      sb.append("&")
+      // title
+      sb.append("chtt=").append(urlEncode(title))
+      sb.append("&")
+      // axis locations
+      sb.append("chxt=y,x")
+      sb.append("&")
+      // labels
+      sb.append("chxl=1:|")
+      sb.append(loads.mkString("|"))
+      sb.append("&")
 
-    val sb = new StringBuilder
-    sb.append(BaseUrl)
-    // bar chart
-    sb.append("cht=bvg")
-    sb.append("&")
-    // size
-    sb.append("chs=").append(ChartWidth).append("x").append(ChartHeight)
-    sb.append("&")
-    // title
-    sb.append("chtt=").append(urlEncode(title))
-    sb.append("&")
-    // axis locations
-    sb.append("chxt=y,x")
-    sb.append("&")
-    // labels
-    sb.append("chxl=1:|")
-    sb.append(loads.mkString("|"))
-    sb.append("&")
+      // label color and font
+      //sb.append("chxs=2,D65D82,11.5,0,lt,D65D82")
+      //sb.append("&")
 
-    // label color and font
-    //sb.append("chxs=2,D65D82,11.5,0,lt,D65D82")
-    //sb.append("&")
+      // legend
+      val legendStats = statsByTimestamp.values.map(_.head).toSeq
+      appendLegend(legendStats, sb, legend)
+      sb.append("&")
+      // bar spacing
+      sb.append("chbh=a,4,20")
+      sb.append("&")
+      // bar colors
+      barColors(statsByTimestamp.size, sb)
+      sb.append("&")
 
-    // legend
-    val legendStats = statsByTimestamp.values.map(_.head).toSeq
-    appendLegend(legendStats, sb, legend)
-    sb.append("&")
-    // bar spacing
-    sb.append("chbh=a,4,20")
-    sb.append("&")
-    // bar colors
-    barColors(statsByTimestamp.size, sb)
-    sb.append("&")
+      // data series
+      val loadStr = loads.mkString(",")
+      sb.append("chd=t:")
+      val maxValue = allStats.map(_.tps).max
+      val tpsSeries: Iterable[String] =
+        for (statsSeq ← statsByTimestamp.values) yield {
+          statsSeq.map(_.tps).mkString(",")
+        }
+      sb.append(tpsSeries.mkString("|"))
 
-    // data series
-    val loadStr = loads.mkString(",")
-    sb.append("chd=t:")
-    val maxValue = allStats.map(_.tps).max
-    val tpsSeries: Iterable[String] =
-      for (statsSeq ← statsByTimestamp.values) yield {
-        statsSeq.map(_.tps).mkString(",")
-      }
-    sb.append(tpsSeries.mkString("|"))
+      // y range
+      sb.append("&")
+      sb.append("chxr=0,0,").append(maxValue)
+      sb.append("&")
+      sb.append("chds=0,").append(maxValue)
+      sb.append("&")
 
-    // y range
-    sb.append("&")
-    sb.append("chxr=0,0,").append(maxValue)
-    sb.append("&")
-    sb.append("chds=0,").append(maxValue)
-    sb.append("&")
+      // grid lines
+      appendGridSpacing(maxValue.toLong, sb)
 
-    // grid lines
-    appendGridSpacing(maxValue.toLong, sb)
-
-    return sb.toString
+      sb.toString
+    }
   }
 
   /**
    * Builds a bar chart for all percentiles and the mean in the statistics.
    */
   def percentilesAndMeanChartUrl(statistics: Seq[Stats], title: String, legend: Stats ⇒ String): String = {
-    if (statistics.isEmpty) return ""
+    if (statistics.isEmpty) ""
+    else {
+      val current = statistics.last
 
-    val current = statistics.last
+      val sb = new StringBuilder
+      sb.append(BaseUrl)
+      // bar chart
+      sb.append("cht=bvg")
+      sb.append("&")
+      // size
+      sb.append("chs=").append(ChartWidth).append("x").append(ChartHeight)
+      sb.append("&")
+      // title
+      sb.append("chtt=").append(urlEncode(title))
+      sb.append("&")
+      // axis locations
+      sb.append("chxt=y,x,y")
+      sb.append("&")
+      // labels
+      percentileLabels(current.percentiles, sb)
+      sb.append("|mean")
+      sb.append("|2:|min|mean|median")
+      sb.append("&")
+      // label positions
+      sb.append("chxp=2,").append(current.min).append(",").append(current.mean).append(",")
+        .append(current.median)
+      sb.append("&")
+      // label color and font
+      sb.append("chxs=2,D65D82,11.5,0,lt,D65D82")
+      sb.append("&")
+      // lines for min, mean, median
+      sb.append("chxtc=2,-1000")
+      sb.append("&")
+      // legend
+      appendLegend(statistics, sb, legend)
+      sb.append("&")
+      // bar spacing
+      sb.append("chbh=a,4,20")
+      sb.append("&")
+      // bar colors
+      barColors(statistics.size, sb)
+      sb.append("&")
 
-    val sb = new StringBuilder
-    sb.append(BaseUrl)
-    // bar chart
-    sb.append("cht=bvg")
-    sb.append("&")
-    // size
-    sb.append("chs=").append(ChartWidth).append("x").append(ChartHeight)
-    sb.append("&")
-    // title
-    sb.append("chtt=").append(urlEncode(title))
-    sb.append("&")
-    // axis locations
-    sb.append("chxt=y,x,y")
-    sb.append("&")
-    // labels
-    percentileLabels(current.percentiles, sb)
-    sb.append("|mean")
-    sb.append("|2:|min|mean|median")
-    sb.append("&")
-    // label positions
-    sb.append("chxp=2,").append(current.min).append(",").append(current.mean).append(",")
-      .append(current.median)
-    sb.append("&")
-    // label color and font
-    sb.append("chxs=2,D65D82,11.5,0,lt,D65D82")
-    sb.append("&")
-    // lines for min, mean, median
-    sb.append("chxtc=2,-1000")
-    sb.append("&")
-    // legend
-    appendLegend(statistics, sb, legend)
-    sb.append("&")
-    // bar spacing
-    sb.append("chbh=a,4,20")
-    sb.append("&")
-    // bar colors
-    barColors(statistics.size, sb)
-    sb.append("&")
+      // data series
+      val maxValue = statistics.map(_.percentiles.last._2).max
+      sb.append("chd=t:")
+      dataSeries(statistics.map(_.percentiles), statistics.map(_.mean), sb)
 
-    // data series
-    val maxValue = statistics.map(_.percentiles.last._2).max
-    sb.append("chd=t:")
-    dataSeries(statistics.map(_.percentiles), statistics.map(_.mean), sb)
+      // y range
+      sb.append("&")
+      sb.append("chxr=0,0,").append(maxValue).append("|2,0,").append(maxValue)
+      sb.append("&")
+      sb.append("chds=0,").append(maxValue)
+      sb.append("&")
 
-    // y range
-    sb.append("&")
-    sb.append("chxr=0,0,").append(maxValue).append("|2,0,").append(maxValue)
-    sb.append("&")
-    sb.append("chds=0,").append(maxValue)
-    sb.append("&")
+      // grid lines
+      appendGridSpacing(maxValue, sb)
 
-    // grid lines
-    appendGridSpacing(maxValue, sb)
-
-    return sb.toString
+      sb.toString
+    }
   }
 
   private def percentileLabels(percentiles: TreeMap[Int, Long], sb: StringBuilder) {
@@ -197,108 +199,109 @@ object GoogleChartBuilder {
   }
 
   def latencyAndThroughputChartUrl(statistics: Seq[Stats], title: String): String = {
-    if (statistics.isEmpty) return ""
+    if (statistics.isEmpty) ""
+    else {
+      val sb = new StringBuilder
+      sb.append(BaseUrl)
+      // line chart
+      sb.append("cht=lxy")
+      sb.append("&")
+      // size
+      sb.append("chs=").append(ChartWidth).append("x").append(ChartHeight)
+      sb.append("&")
+      // title
+      sb.append("chtt=").append(urlEncode(title))
+      sb.append("&")
+      // axis locations
+      sb.append("chxt=x,y,r,x,y,r")
+      sb.append("&")
+      // labels
+      sb.append("chxl=3:|clients|4:|Latency+(us)|5:|Throughput+(tps)")
+      sb.append("&")
+      // label color and font
+      sb.append("chxs=0,676767,11.5,0,lt,676767|1,676767,11.5,0,lt,676767|2,676767,11.5,0,lt,676767")
+      sb.append("&")
+      sb.append("chco=")
+      val seriesColors = List("25B33B", "3072F3", "FF0000", "37F0ED", "FF9900")
+      sb.append(seriesColors.mkString(","))
+      sb.append("&")
+      // legend
+      sb.append("chdl=5th%20Percentile|Median|95th%20Percentile|Mean|Throughput")
+      sb.append("&")
 
-    val sb = new StringBuilder
-    sb.append(BaseUrl)
-    // line chart
-    sb.append("cht=lxy")
-    sb.append("&")
-    // size
-    sb.append("chs=").append(ChartWidth).append("x").append(ChartHeight)
-    sb.append("&")
-    // title
-    sb.append("chtt=").append(urlEncode(title))
-    sb.append("&")
-    // axis locations
-    sb.append("chxt=x,y,r,x,y,r")
-    sb.append("&")
-    // labels
-    sb.append("chxl=3:|clients|4:|Latency+(us)|5:|Throughput+(tps)")
-    sb.append("&")
-    // label color and font
-    sb.append("chxs=0,676767,11.5,0,lt,676767|1,676767,11.5,0,lt,676767|2,676767,11.5,0,lt,676767")
-    sb.append("&")
-    sb.append("chco=")
-    val seriesColors = List("25B33B", "3072F3", "FF0000", "37F0ED", "FF9900")
-    sb.append(seriesColors.mkString(","))
-    sb.append("&")
-    // legend
-    sb.append("chdl=5th%20Percentile|Median|95th%20Percentile|Mean|Throughput")
-    sb.append("&")
+      sb.append("chdlp=b")
+      sb.append("&")
 
-    sb.append("chdlp=b")
-    sb.append("&")
+      sb.append("chls=1|1|1")
+      sb.append("&")
 
-    sb.append("chls=1|1|1")
-    sb.append("&")
+      sb.append("chls=1|1|1")
+      sb.append("&")
 
-    sb.append("chls=1|1|1")
-    sb.append("&")
+      // margins
+      sb.append("chma=5,5,5,25")
+      sb.append("&")
 
-    // margins
-    sb.append("chma=5,5,5,25")
-    sb.append("&")
+      // data points
+      sb.append("chm=")
+      val chmStr = seriesColors.zipWithIndex.map(each ⇒ "o," + each._1 + "," + each._2 + ",-1,7").mkString("|")
+      sb.append(chmStr)
+      sb.append("&")
 
-    // data points
-    sb.append("chm=")
-    val chmStr = seriesColors.zipWithIndex.map(each ⇒ "o," + each._1 + "," + each._2 + ",-1,7").mkString("|")
-    sb.append(chmStr)
-    sb.append("&")
+      // data series
+      val loadStr = statistics.map(_.load).mkString(",")
+      sb.append("chd=t:")
+      val maxP = 95
+      val percentiles = List(5, 50, maxP)
+      val maxValue = statistics.map(_.percentiles(maxP)).max
+      val percentileSeries: List[String] =
+        for (p ← percentiles) yield {
+          loadStr + "|" + statistics.map(_.percentiles(p)).mkString(",")
+        }
+      sb.append(percentileSeries.mkString("|"))
 
-    // data series
-    val loadStr = statistics.map(_.load).mkString(",")
-    sb.append("chd=t:")
-    val maxP = 95
-    val percentiles = List(5, 50, maxP)
-    val maxValue = statistics.map(_.percentiles(maxP)).max
-    val percentileSeries: List[String] =
-      for (p ← percentiles) yield {
-        loadStr + "|" + statistics.map(_.percentiles(p)).mkString(",")
+      sb.append("|")
+      sb.append(loadStr).append("|")
+      val meanSeries = statistics.map(s ⇒ formatDouble(s.mean)).mkString(",")
+      sb.append(meanSeries)
+
+      sb.append("|")
+      val maxTps: Double = statistics.map(_.tps).max
+      sb.append(loadStr).append("|")
+      val tpsSeries = statistics.map(s ⇒ formatDouble(s.tps)).mkString(",")
+      sb.append(tpsSeries)
+
+      val minLoad = statistics.head.load
+      val maxLoad = statistics.last.load
+
+      // y range
+      sb.append("&")
+      sb.append("chxr=0,").append(minLoad).append(",").append(maxLoad).append(",4").append("|1,0,").append(maxValue).append("|2,0,")
+        .append(formatDouble(maxTps))
+      sb.append("&")
+
+      sb.append("chds=")
+      for (p ← percentiles) {
+        sb.append(minLoad).append(",").append(maxLoad)
+        sb.append(",0,").append(maxValue)
+        sb.append(",")
       }
-    sb.append(percentileSeries.mkString("|"))
-
-    sb.append("|")
-    sb.append(loadStr).append("|")
-    val meanSeries = statistics.map(s ⇒ formatDouble(s.mean)).mkString(",")
-    sb.append(meanSeries)
-
-    sb.append("|")
-    val maxTps: Double = statistics.map(_.tps).max
-    sb.append(loadStr).append("|")
-    val tpsSeries = statistics.map(s ⇒ formatDouble(s.tps)).mkString(",")
-    sb.append(tpsSeries)
-
-    val minLoad = statistics.head.load
-    val maxLoad = statistics.last.load
-
-    // y range
-    sb.append("&")
-    sb.append("chxr=0,").append(minLoad).append(",").append(maxLoad).append(",4").append("|1,0,").append(maxValue).append("|2,0,")
-      .append(formatDouble(maxTps))
-    sb.append("&")
-
-    sb.append("chds=")
-    for (p ← percentiles) {
       sb.append(minLoad).append(",").append(maxLoad)
-      sb.append(",0,").append(maxValue)
+      sb.append(",0,").append(formatDouble(maxValue))
       sb.append(",")
+      sb.append(minLoad).append(",").append(maxLoad)
+      sb.append(",0,").append(formatDouble(maxTps))
+      sb.append("&")
+
+      // label positions
+      sb.append("chxp=3,").append("50").append("|4,").append("100").append("|5,").append("100")
+      sb.append("&")
+
+      // grid lines
+      appendGridSpacing(maxValue, sb)
+
+      sb.toString
     }
-    sb.append(minLoad).append(",").append(maxLoad)
-    sb.append(",0,").append(formatDouble(maxValue))
-    sb.append(",")
-    sb.append(minLoad).append(",").append(maxLoad)
-    sb.append(",0,").append(formatDouble(maxTps))
-    sb.append("&")
-
-    // label positions
-    sb.append("chxp=3,").append("50").append("|4,").append("100").append("|5,").append("100")
-    sb.append("&")
-
-    // grid lines
-    appendGridSpacing(maxValue, sb)
-
-    return sb.toString
   }
 
   def formatDouble(value: Double): String = {
diff --git a/akka-actor/src/main/scala/akka/util/BoundedBlockingQueue.scala b/akka-actor/src/main/scala/akka/util/BoundedBlockingQueue.scala
index c7c8308de0..613599fa8e 100644
--- a/akka-actor/src/main/scala/akka/util/BoundedBlockingQueue.scala
+++ b/akka-actor/src/main/scala/akka/util/BoundedBlockingQueue.scala
@@ -7,6 +7,7 @@ package akka.util
 import java.util.concurrent.locks.ReentrantLock
 import java.util.concurrent.{ TimeUnit, BlockingQueue }
 import java.util.{ AbstractQueue, Queue, Collection, Iterator }
+import annotation.tailrec
 
 /**
  * BoundedBlockingQueue wraps any Queue and turns the result into a BlockingQueue with a limited capacity
@@ -80,15 +81,17 @@ class BoundedBlockingQueue[E <: AnyRef](
     var nanos = unit.toNanos(timeout)
     lock.lockInterruptibly()
     try {
-      while (backing.size() == maxCapacity) {
-        if (nanos <= 0)
-          return false
-        else
-          nanos = notFull.awaitNanos(nanos)
-      }
-      require(backing.offer(e)) //Should never fail
-      notEmpty.signal()
-      true
+      @tailrec def awaitNotFull(ns: Long): Boolean =
+        if (backing.size() == maxCapacity) {
+          if (ns > 0) awaitNotFull(notFull.awaitNanos(ns))
+          else false
+        } else true
+
+      if (awaitNotFull(nanos)) {
+        require(backing.offer(e)) //Should never fail
+        notEmpty.signal()
+        true
+      } else false
     } finally {
       lock.unlock()
     }
@@ -208,17 +211,14 @@ class BoundedBlockingQueue[E <: AnyRef](
     else {
       lock.lock()
       try {
-        var n = 0
-        var e: E = null.asInstanceOf[E]
-        while (n < maxElements) {
-          backing.poll() match {
-            case null ⇒ return n
-            case e ⇒
-              c add e
-              n += 1
-          }
-        }
-        n
+        @tailrec def drainOne(n: Int): Int =
+          if (n < maxElements) {
+            backing.poll() match {
+              case null ⇒ n
+              case e    ⇒ c add e; drainOne(n + 1)
+            }
+          } else n
+        drainOne(0)
       } finally {
         lock.unlock()
       }
@@ -285,14 +285,14 @@ class BoundedBlockingQueue[E <: AnyRef](
           last = -1 //To avoid 2 subsequent removes without a next in between
           lock.lock()
           try {
-            val i = backing.iterator()
-            while (i.hasNext) {
+            @tailrec def removeTarget(i: Iterator[E] = backing.iterator()): Unit = if (i.hasNext) {
               if (i.next eq target) {
                 i.remove()
                 notFull.signal()
-                return ()
-              }
+              } else removeTarget(i)
             }
+
+            removeTarget()
           } finally {
             lock.unlock()
           }
diff --git a/akka-actor/src/main/scala/akka/util/SubclassifiedIndex.scala b/akka-actor/src/main/scala/akka/util/SubclassifiedIndex.scala
index 4149a0b0b1..d07fff3a32 100644
--- a/akka-actor/src/main/scala/akka/util/SubclassifiedIndex.scala
+++ b/akka-actor/src/main/scala/akka/util/SubclassifiedIndex.scala
@@ -79,14 +79,14 @@ class SubclassifiedIndex[K, V] private (private var values: Set[V])(implicit sc:
    * Add key to this index which inherits its value set from the most specific
    * super-class which is known.
    */
-  def addKey(key: K): Changes = {
-    for (n ← subkeys) {
-      if (sc.isEqual(n.key, key)) return Nil
-      else if (sc.isSubclass(key, n.key)) return n.addKey(key)
+  def addKey(key: K): Changes =
+    subkeys collectFirst {
+      case n if sc.isEqual(n.key, key)    ⇒ Nil
+      case n if sc.isSubclass(key, n.key) ⇒ n.addKey(key)
+    } getOrElse {
+      integrate(new Nonroot(key, values))
+      List((key, values))
     }
-    integrate(new Nonroot(key, values))
-    (key, values) :: Nil
-  }
 
   /**
    * Add value to all keys which are subclasses of the given key. If the key
diff --git a/akka-zeromq/src/main/scala/akka/zeromq/package.scala b/akka-zeromq/src/main/scala/akka/zeromq/package.scala
index c10ad9eb85..2795505fa0 100644
--- a/akka-zeromq/src/main/scala/akka/zeromq/package.scala
+++ b/akka-zeromq/src/main/scala/akka/zeromq/package.scala
@@ -11,14 +11,6 @@ import actor.ActorSystem
  * A package object with an implicit conversion for the actor system as a convenience
  */
 package object zeromq {
-
-  /**
-   * Creates a zeromq actor system implicitly
-   * @param system
-   * @return An augmented [[akka.actor.ActorSystem]]
-   */
-  implicit def zeromqSystem(system: ActorSystem): ZeroMQExtension = ZeroMQExtension(system)
-
   /**
    * Convenience accessor to subscribe to all events
    */