diff --git a/akka-http-core/src/main/scala/akka/http/impl/engine/client/PoolGateway.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/client/PoolGateway.scala
index 470a685d1e..0dca57656d 100644
--- a/akka-http-core/src/main/scala/akka/http/impl/engine/client/PoolGateway.scala
+++ b/akka-http-core/src/main/scala/akka/http/impl/engine/client/PoolGateway.scala
@@ -41,7 +41,7 @@ private[http] class PoolGateway(hcps: HostConnectionPoolSetup,
   private val state = {
     val shutdownCompletedPromise = Promise[Unit]()
     val props = Props(new PoolInterfaceActor(hcps, shutdownCompletedPromise, this)).withDeploy(Deploy.local)
-    val ref = system.actorOf(props, PoolInterfaceActor.name.next())
+    val ref = system.actorOf(props, PoolInterfaceActor.names.next())
     new AtomicReference[State](Running(ref, _shutdownStartedPromise, shutdownCompletedPromise))
   }
 
diff --git a/akka-http-core/src/main/scala/akka/http/impl/engine/client/PoolInterfaceActor.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/client/PoolInterfaceActor.scala
index 5768324378..f4babf1915 100644
--- a/akka-http-core/src/main/scala/akka/http/impl/engine/client/PoolInterfaceActor.scala
+++ b/akka-http-core/src/main/scala/akka/http/impl/engine/client/PoolInterfaceActor.scala
@@ -27,7 +27,7 @@ private object PoolInterfaceActor {
 
   case object Shutdown extends DeadLetterSuppression
 
-  val name = new SeqActorName("PoolInterfaceActor")
+  val names = SeqActorName("PoolInterfaceActor")
 }
 
 /**
diff --git a/akka-http-core/src/main/scala/akka/http/impl/engine/client/PoolSlot.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/client/PoolSlot.scala
index 01c3584c5e..ce5b7ab76c 100644
--- a/akka-http-core/src/main/scala/akka/http/impl/engine/client/PoolSlot.scala
+++ b/akka-http-core/src/main/scala/akka/http/impl/engine/client/PoolSlot.scala
@@ -35,7 +35,7 @@ private object PoolSlot {
     final case class Disconnected(slotIx: Int, failedRequests: Int) extends SlotEvent
   }
 
-  private val slotProcessorActorName = new SeqActorName("SlotProcessor")
+  private val slotProcessorActorName = SeqActorName("SlotProcessor")
 
   /*
     Stream Setup
diff --git a/akka-stream/src/main/scala/akka/stream/ActorMaterializer.scala b/akka-stream/src/main/scala/akka/stream/ActorMaterializer.scala
index fcef4e3243..12664eb557 100644
--- a/akka-stream/src/main/scala/akka/stream/ActorMaterializer.scala
+++ b/akka-stream/src/main/scala/akka/stream/ActorMaterializer.scala
@@ -59,8 +59,7 @@ object ActorMaterializer {
       system.dispatchers,
       context.actorOf(StreamSupervisor.props(materializerSettings, haveShutDown).withDispatcher(materializerSettings.dispatcher), StreamSupervisor.nextName()),
       haveShutDown,
-      FlowNameCounter(system).counter,
-      namePrefix)
+      FlowNames(system).names.copy(namePrefix))
   }
 
   /**
diff --git a/akka-stream/src/main/scala/akka/stream/impl/ActorMaterializerImpl.scala b/akka-stream/src/main/scala/akka/stream/impl/ActorMaterializerImpl.scala
index 037c488f31..7452eefa36 100644
--- a/akka-stream/src/main/scala/akka/stream/impl/ActorMaterializerImpl.scala
+++ b/akka-stream/src/main/scala/akka/stream/impl/ActorMaterializerImpl.scala
@@ -27,8 +27,7 @@ private[akka] case class ActorMaterializerImpl(system: ActorSystem,
                                                dispatchers: Dispatchers,
                                                supervisor: ActorRef,
                                                haveShutDown: AtomicBoolean,
-                                               flowNameCounter: AtomicLong,
-                                               namePrefix: String) extends ActorMaterializer {
+                                               flowNames: SeqActorName) extends ActorMaterializer {
   import akka.stream.impl.Stages._
   private val logger = Logging.getLogger(system, this)
 
@@ -42,11 +41,9 @@ private[akka] case class ActorMaterializerImpl(system: ActorSystem,
 
   override def isShutdown: Boolean = haveShutDown.get()
 
-  override def withNamePrefix(name: String): Materializer = this.copy(namePrefix = name)
+  override def withNamePrefix(name: String): Materializer = this.copy(flowNames = flowNames.copy(name))
 
-  private[this] def nextFlowNameCount(): Long = flowNameCounter.incrementAndGet() // TODO use SeqActorName instead
-
-  private[this] def createFlowName(): String = s"$namePrefix-${nextFlowNameCount()}"
+  private[this] def createFlowName(): String = flowNames.next()
 
   private val initialAttributes = Attributes(
     Attributes.InputBuffer(settings.initialInputBufferSize, settings.maxInputBufferSize) ::
@@ -195,17 +192,17 @@ private[akka] case class ActorMaterializerImpl(system: ActorSystem,
 /**
  * INTERNAL API
  */
-private[akka] object FlowNameCounter extends ExtensionId[FlowNameCounter] with ExtensionIdProvider {
-  override def get(system: ActorSystem): FlowNameCounter = super.get(system)
-  override def lookup() = FlowNameCounter
-  override def createExtension(system: ExtendedActorSystem): FlowNameCounter = new FlowNameCounter
+private[akka] object FlowNames extends ExtensionId[FlowNames] with ExtensionIdProvider {
+  override def get(system: ActorSystem): FlowNames = super.get(system)
+  override def lookup() = FlowNames
+  override def createExtension(system: ExtendedActorSystem): FlowNames = new FlowNames
 }
 
 /**
  * INTERNAL API
  */
-private[akka] class FlowNameCounter extends Extension {
-  val counter = new AtomicLong(0)
+private[akka] class FlowNames extends Extension {
+  val names = SeqActorName("Flow")
 }
 
 /**
@@ -215,7 +212,7 @@ private[akka] object StreamSupervisor {
   def props(settings: ActorMaterializerSettings, haveShutDown: AtomicBoolean): Props =
     Props(new StreamSupervisor(settings, haveShutDown)).withDeploy(Deploy.local)
 
-  private val actorName = new SeqActorName("StreamSupervisor")
+  private val actorName = SeqActorName("StreamSupervisor")
   def nextName(): String = actorName.next()
 
   final case class Materialize(props: Props, name: String)
diff --git a/akka-stream/src/main/scala/akka/stream/impl/SeqActorName.scala b/akka-stream/src/main/scala/akka/stream/impl/SeqActorName.scala
index f88949c1a2..b088e0b95b 100644
--- a/akka-stream/src/main/scala/akka/stream/impl/SeqActorName.scala
+++ b/akka-stream/src/main/scala/akka/stream/impl/SeqActorName.scala
@@ -13,6 +13,16 @@ import java.util.concurrent.atomic.AtomicLong
  * Generator of sequentially numbered actor names.
  * Pulled out from HTTP internals, most often used used by streams which materialize actors directly
  */
-private[akka] final class SeqActorName(prefix: String) extends AtomicLong {
-  def next(): String = prefix + '-' + getAndIncrement()
+abstract class SeqActorName {
+  def next(): String
+  def copy(name: String): SeqActorName
+}
+object SeqActorName {
+  def apply(prefix: String) = new SeqActorNameImpl(prefix, new AtomicLong(0))
+}
+
+private[akka] final class SeqActorNameImpl(val prefix: String, counter: AtomicLong) extends SeqActorName {
+  def next(): String = prefix + '-' + counter.getAndIncrement()
+
+  def copy(newPrefix: String): SeqActorName = new SeqActorNameImpl(newPrefix, counter)
 }