diff --git a/akka-cluster/src/main/scala/akka/cluster/ClusterDaemon.scala b/akka-cluster/src/main/scala/akka/cluster/ClusterDaemon.scala
index d2f08d15eb..879f0db6db 100644
--- a/akka-cluster/src/main/scala/akka/cluster/ClusterDaemon.scala
+++ b/akka-cluster/src/main/scala/akka/cluster/ClusterDaemon.scala
@@ -697,7 +697,7 @@ private[cluster] final class ClusterCoreDaemon(publisher: ActorRef) extends Acto
     val localUnreachableMembers = localOverview.unreachable
 
     val hasPartionHandoffCompletedSuccessfully: Boolean = {
-      // FIXME implement partion handoff and a check if it is completed - now just returns TRUE - e.g. has completed successfully
+      // TODO implement partion handoff and a check if it is completed - now just returns TRUE - e.g. has completed successfully
       true
     }
 
diff --git a/akka-cluster/src/main/scala/akka/cluster/ClusterHeartbeat.scala b/akka-cluster/src/main/scala/akka/cluster/ClusterHeartbeat.scala
index 7bc91d4516..bcfde2f07e 100644
--- a/akka-cluster/src/main/scala/akka/cluster/ClusterHeartbeat.scala
+++ b/akka-cluster/src/main/scala/akka/cluster/ClusterHeartbeat.scala
@@ -246,7 +246,7 @@ private[cluster] case class ClusterHeartbeatSenderState private (
   ending: Map[Address, Int] = Map.empty,
   heartbeatRequest: Map[Address, Deadline] = Map.empty) {
 
-  // FIXME can be disabled as optimization
+  // TODO can be disabled as optimization
   assertInvariants()
 
   private def assertInvariants(): Unit = {
diff --git a/akka-cluster/src/main/scala/akka/cluster/Gossip.scala b/akka-cluster/src/main/scala/akka/cluster/Gossip.scala
index 0212988b5d..4bae2006bc 100644
--- a/akka-cluster/src/main/scala/akka/cluster/Gossip.scala
+++ b/akka-cluster/src/main/scala/akka/cluster/Gossip.scala
@@ -64,7 +64,7 @@ private[cluster] case class Gossip(
   version: VectorClock = VectorClock()) // vector clock version
   extends Versioned[Gossip] {
 
-  // FIXME can be disabled as optimization
+  // TODO can be disabled as optimization
   assertInvariants()
 
   private def assertInvariants(): Unit = {
diff --git a/akka-contrib/src/multi-jvm/scala/akka/contrib/pattern/ClusterSingletonManagerChaosSpec.scala b/akka-contrib/src/multi-jvm/scala/akka/contrib/pattern/ClusterSingletonManagerChaosSpec.scala
index 672b07a0de..6ffbea6ec9 100644
--- a/akka-contrib/src/multi-jvm/scala/akka/contrib/pattern/ClusterSingletonManagerChaosSpec.scala
+++ b/akka-contrib/src/multi-jvm/scala/akka/contrib/pattern/ClusterSingletonManagerChaosSpec.scala
@@ -146,10 +146,9 @@ class ClusterSingletonManagerChaosSpec extends MultiNodeSpec(ClusterSingletonMan
     }
 
     "take over when three oldest nodes crash in 6 nodes cluster" in within(90 seconds) {
-      // FIXME change those to DeadLetterFilter
-      system.eventStream.publish(Mute(EventFilter.warning(pattern = ".*received dead letter from.*")))
-      system.eventStream.publish(Mute(EventFilter.error(pattern = ".*Disassociated.*")))
-      system.eventStream.publish(Mute(EventFilter.error(pattern = ".*Association failed.*")))
+      // mute logging of deadLetters during shutdown of systems
+      if (!log.isDebugEnabled)
+        system.eventStream.publish(Mute(DeadLettersFilter[Any]))
       enterBarrier("logs-muted")
 
       crash(first, second, third)
diff --git a/akka-contrib/src/multi-jvm/scala/akka/contrib/pattern/ClusterSingletonManagerSpec.scala b/akka-contrib/src/multi-jvm/scala/akka/contrib/pattern/ClusterSingletonManagerSpec.scala
index 048f81afd7..3199ed3d8f 100644
--- a/akka-contrib/src/multi-jvm/scala/akka/contrib/pattern/ClusterSingletonManagerSpec.scala
+++ b/akka-contrib/src/multi-jvm/scala/akka/contrib/pattern/ClusterSingletonManagerSpec.scala
@@ -345,10 +345,9 @@ class ClusterSingletonManagerSpec extends MultiNodeSpec(ClusterSingletonManagerS
     }
 
     "take over when oldest crashes in 5 nodes cluster" in within(60 seconds) {
-      // FIXME change those to DeadLetterFilter
-      system.eventStream.publish(Mute(EventFilter.warning(pattern = ".*received dead letter from.*")))
-      system.eventStream.publish(Mute(EventFilter.error(pattern = ".*Disassociated.*")))
-      system.eventStream.publish(Mute(EventFilter.error(pattern = ".*Association failed.*")))
+      // mute logging of deadLetters during shutdown of systems
+      if (!log.isDebugEnabled)
+        system.eventStream.publish(Mute(DeadLettersFilter[Any]))
       enterBarrier("logs-muted")
 
       crash(second)