diff --git a/akka-actor-tests/src/test/scala/akka/util/IndexSpec.scala b/akka-actor-tests/src/test/scala/akka/util/IndexSpec.scala
index 499f671981..94a936d101 100644
--- a/akka-actor-tests/src/test/scala/akka/util/IndexSpec.scala
+++ b/akka-actor-tests/src/test/scala/akka/util/IndexSpec.scala
@@ -5,6 +5,8 @@ package akka.util
 
 import org.scalatest.WordSpec
 import org.scalatest.matchers.MustMatchers
+import scala.actors.Actor._
+import java.util.concurrent.CountDownLatch
 
 class IndexSpec extends WordSpec with MustMatchers {
 
@@ -27,17 +29,17 @@ class IndexSpec extends WordSpec with MustMatchers {
     "take and return a value" in {
       val index = emptyIndex
       index.put("s1", 1)
-      assert(index.valueIterator("s1").toSet === Set(1))
+      index.valueIterator("s1").toSet must be === Set(1)
     }
     "take and return several values" in {
       val index = emptyIndex
-      assert(index.put("s1", 1))
-      assert(!index.put("s1", 1))
+      index.put("s1", 1) must be === true
+      index.put("s1", 1) must be === false
       index.put("s1", 2)
       index.put("s1", 3)
       index.put("s2", 4)
-      assert(index.valueIterator("s1").toSet === Set(1, 2, 3))
-      assert(index.valueIterator("s2").toSet === Set(4))
+      index.valueIterator("s1").toSet must be === Set(1, 2, 3)
+      index.valueIterator("s2").toSet must be === Set(4)
     }
     "remove values" in {
       val index = emptyIndex
@@ -46,16 +48,16 @@ class IndexSpec extends WordSpec with MustMatchers {
       index.put("s2", 1)
       index.put("s2", 2)
       //Remove value
-      assert(index.remove("s1", 1))
-      assert(index.remove("s1", 1) === false)
-      assert(index.valueIterator("s1").toSet === Set(2))
+      index.remove("s1", 1) must be === true
+      index.remove("s1", 1) must be === false
+      index.valueIterator("s1").toSet must be === Set(2)
       //Remove key
       index.remove("s2") match {
-        case Some(iter) ⇒ assert(iter.toSet === Set(1, 2))
+        case Some(iter) ⇒ iter.toSet must be === Set(1, 2)
         case None       ⇒ fail()
       }
-      assert(index.remove("s2") === None)
-      assert(index.valueIterator("s2").toSet === Set())
+      index.remove("s2") must be === None
+      index.valueIterator("s2").toSet must be === Set()
     }
     "remove the specified value" in {
       val index = emptyIndex
@@ -67,9 +69,9 @@ class IndexSpec extends WordSpec with MustMatchers {
       index.put("s3", 2)
 
       index.removeValue(1)
-      assert(index.valueIterator("s1").toSet === Set(2, 3))
-      assert(index.valueIterator("s2").toSet === Set(2))
-      assert(index.valueIterator("s3").toSet === Set(2))
+      index.valueIterator("s1").toSet must be === Set(2, 3)
+      index.valueIterator("s2").toSet must be === Set(2)
+      index.valueIterator("s3").toSet must be === Set(2)
     }
     "apply a function for all key-value pairs and find every value" in {
       val index = indexWithValues
@@ -77,14 +79,58 @@ class IndexSpec extends WordSpec with MustMatchers {
       var valueCount = 0
       index.foreach((key, value) ⇒ {
         valueCount = valueCount + 1
-        assert(index.findValue(key)(_ == value) === Some(value))
+        index.findValue(key)(_ == value) must be === Some(value)
       })
-      assert(valueCount === 6)
+      valueCount must be === 6
     }
     "be cleared" in {
       val index = indexWithValues
+      index.isEmpty must be === false
       index.clear()
-      assert(index.isEmpty)
+      index.isEmpty must be === true
+    }
+    "be able to be accessed in parallel" in {
+      val index = new Index[Int, Int](100, (a, b) ⇒ a.compareTo(b))
+      val iterations = 500
+      val latch = new CountDownLatch(List(100, 50, 2, 100).map(_ * iterations).fold(0)(_ + _))
+      //Fill
+      for (key ← 1 to 10; value ← 1 to 10)
+        index.put(key, value)
+      //Perform operations in parallell
+      for (_ ← 1 to iterations) {
+        //Put actors
+        actor {
+          for (key ← 1 to 10; value ← 1 to 10)
+            actor {
+              index.put(key, value)
+              latch.countDown() //100
+            }
+        }
+        //Remove actors
+        actor {
+          for (key ← 1 to 10; value ← 1 to 5)
+            actor {
+              index.remove(key, value)
+              latch.countDown() //50
+            }
+          for (key ← 9 to 10)
+            actor {
+              index.remove(key)
+              latch.countDown() //2
+            }
+        }
+        //Read actors
+        actor {
+          for (key ← 1 to 10; value ← 1 to 10)
+            actor {
+              val values = index.valueIterator(key)
+              if (key < 9 && value > 5)
+                (values contains value) must be === true
+              latch.countDown() //100
+            }
+        }
+      }
+      latch.await()
     }
   }
 }
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