diff --git a/akka-actor/src/main/scala/akka/actor/Stash.scala b/akka-actor/src/main/scala/akka/actor/Stash.scala
index feaec7e64b..1abbb9f6fb 100644
--- a/akka-actor/src/main/scala/akka/actor/Stash.scala
+++ b/akka-actor/src/main/scala/akka/actor/Stash.scala
@@ -123,14 +123,8 @@ private[akka] trait StashSupport {
 
   /* The capacity of the stash. Configured in the actor's mailbox or dispatcher config.
    */
-  private val capacity: Int = {
-    val dispatcher = context.system.settings.config.getConfig(context.props.dispatcher)
-    val fallback = dispatcher.withFallback(context.system.settings.config.getConfig(Mailboxes.DefaultMailboxId))
-    val config =
-      if (context.props.mailbox == Mailboxes.DefaultMailboxId) fallback
-      else context.system.settings.config.getConfig(context.props.mailbox).withFallback(fallback)
-    config.getInt("stash-capacity")
-  }
+  private val capacity: Int =
+    context.system.mailboxes.stashCapacity(context.props.dispatcher, context.props.mailbox)
 
   /**
    * INTERNAL API.
diff --git a/akka-actor/src/main/scala/akka/dispatch/Mailboxes.scala b/akka-actor/src/main/scala/akka/dispatch/Mailboxes.scala
index 9f69bcd76a..59c70ee65c 100644
--- a/akka-actor/src/main/scala/akka/dispatch/Mailboxes.scala
+++ b/akka-actor/src/main/scala/akka/dispatch/Mailboxes.scala
@@ -6,7 +6,6 @@ package akka.dispatch
 
 import java.lang.reflect.ParameterizedType
 import java.util.concurrent.ConcurrentHashMap
-
 import akka.ConfigurationException
 import akka.actor.{ Actor, ActorRef, ActorSystem, DeadLetter, Deploy, DynamicAccess, Props }
 import akka.dispatch.sysmsg.{ EarliestFirstSystemMessageList, LatestFirstSystemMessageList, SystemMessage, SystemMessageList }
@@ -14,8 +13,9 @@ import akka.event.EventStream
 import akka.event.Logging.Warning
 import akka.util.Reflect
 import com.typesafe.config.{ Config, ConfigFactory }
-
 import scala.util.control.NonFatal
+import java.util.concurrent.atomic.AtomicReference
+import scala.annotation.tailrec
 
 object Mailboxes {
   final val DefaultMailboxId = "akka.actor.default-mailbox"
@@ -232,4 +232,42 @@ private[akka] class Mailboxes(
       .withFallback(settings.config.getConfig(id))
       .withFallback(defaultMailboxConfig)
   }
+
+  private val stashCapacityCache = new AtomicReference[Map[String, Int]](Map.empty[String, Int])
+  private val defaultStashCapacity: Int =
+    stashCapacityFromConfig(Dispatchers.DefaultDispatcherId, Mailboxes.DefaultMailboxId)
+
+  /**
+   * INTERNAL API: The capacity of the stash. Configured in the actor's mailbox or dispatcher config.
+   */
+  private[akka] final def stashCapacity(dispatcher: String, mailbox: String): Int = {
+
+    @tailrec def updateCache(cache: Map[String, Int], key: String, value: Int): Boolean = {
+      stashCapacityCache.compareAndSet(cache, cache.updated(key, value)) ||
+        updateCache(stashCapacityCache.get, key, value) // recursive, try again
+    }
+
+    if (dispatcher == Dispatchers.DefaultDispatcherId && mailbox == Mailboxes.DefaultMailboxId)
+      defaultStashCapacity
+    else {
+      val cache = stashCapacityCache.get
+      val key = dispatcher + "-" + mailbox
+      cache.get(key) match {
+        case Some(value) ⇒ value
+        case None ⇒
+          val value = stashCapacityFromConfig(dispatcher, mailbox)
+          updateCache(cache, key, value)
+          value
+      }
+    }
+  }
+
+  private def stashCapacityFromConfig(dispatcher: String, mailbox: String): Int = {
+    val disp = settings.config.getConfig(dispatcher)
+    val fallback = disp.withFallback(settings.config.getConfig(Mailboxes.DefaultMailboxId))
+    val config =
+      if (mailbox == Mailboxes.DefaultMailboxId) fallback
+      else settings.config.getConfig(mailbox).withFallback(fallback)
+    config.getInt("stash-capacity")
+  }
 }
diff --git a/akka-bench-jmh/src/main/scala/akka/actor/StashCreationBenchmark.scala b/akka-bench-jmh/src/main/scala/akka/actor/StashCreationBenchmark.scala
new file mode 100644
index 0000000000..54baf8c547
--- /dev/null
+++ b/akka-bench-jmh/src/main/scala/akka/actor/StashCreationBenchmark.scala
@@ -0,0 +1,61 @@
+/**
+ * Copyright (C) 2015 Typesafe Inc. <http://www.typesafe.com>
+ */
+package akka.actor
+
+import scala.concurrent.Await
+import scala.concurrent.duration._
+import akka.testkit.TestProbe
+import com.typesafe.config.ConfigFactory
+import org.openjdk.jmh.annotations._
+import java.util.concurrent.TimeUnit
+
+object StashCreationBenchmark {
+  class StashingActor extends Actor with Stash {
+    def receive = {
+      case msg => sender() ! msg
+    }
+  }
+
+  val props = Props[StashingActor]
+}
+
+@State(Scope.Benchmark)
+@BenchmarkMode(Array(Mode.SampleTime))
+@Fork(3)
+@Warmup(iterations = 5)
+@Measurement(iterations = 10)
+class StashCreationBenchmark {
+  val conf = ConfigFactory.parseString("""
+    my-dispatcher = {
+      stash-capacity = 1000
+    }
+    """)
+  implicit val system: ActorSystem = ActorSystem("StashCreationBenchmark", conf)
+  val probe = TestProbe()
+
+  @TearDown(Level.Trial)
+  def shutdown() {
+    system.terminate()
+    Await.ready(system.whenTerminated, 15.seconds)
+  }
+
+  @Benchmark
+  @OutputTimeUnit(TimeUnit.MICROSECONDS)
+  def testDefault: Boolean = {
+    val stash = system.actorOf(StashCreationBenchmark.props)
+    stash.tell("hello", probe.ref)
+    probe.expectMsg("hello")
+    true
+  }
+
+  @Benchmark
+  @OutputTimeUnit(TimeUnit.MICROSECONDS)
+  def testCustom: Boolean = {
+    val stash = system.actorOf(StashCreationBenchmark.props.withDispatcher("my-dispatcher"))
+    stash.tell("hello", probe.ref)
+    probe.expectMsg("hello")
+    true
+  }
+}
+