diff --git a/build.sbt b/build.sbt
index 85166d74..1dd4af30 100644
--- a/build.sbt
+++ b/build.sbt
@@ -5,7 +5,7 @@ import sbt.Keys.resolvers
 val mainScala        = "2.13.14"
 val scala3Version    = "3.3.3"
 val allScala         = Seq(mainScala, scala3Version)
-val zioVersion       = "2.1.6"
+val zioVersion       = "2.1.8"
 val zioConfigVersion = "4.0.2"
 
 lazy val commonJvmSettings = Seq(
diff --git a/rezilience/shared/src/main/scala/nl/vroste/rezilience/Bulkhead.scala b/rezilience/shared/src/main/scala/nl/vroste/rezilience/Bulkhead.scala
index 82b24b2b..973ad620 100644
--- a/rezilience/shared/src/main/scala/nl/vroste/rezilience/Bulkhead.scala
+++ b/rezilience/shared/src/main/scala/nl/vroste/rezilience/Bulkhead.scala
@@ -83,7 +83,7 @@ object Bulkhead {
       onEnd              = inFlightAndQueued.update(_.endProcess)
       _                 <- ZStream
                              .fromQueueWithShutdown(queue)
-                             .mapZIOPar(maxInFlightCalls) { task =>
+                             .mapZIOPar(maxInFlightCalls, maxInFlightCalls) { task =>
                                ZIO.acquireReleaseWith(onStart)(_ => onEnd)(_ => task)
                              }
                              .runDrain
diff --git a/rezilience/shared/src/test/scala/nl/vroste/rezilience/BulkheadSpec.scala b/rezilience/shared/src/test/scala/nl/vroste/rezilience/BulkheadSpec.scala
index 6377ad92..2be7f2c0 100644
--- a/rezilience/shared/src/test/scala/nl/vroste/rezilience/BulkheadSpec.scala
+++ b/rezilience/shared/src/test/scala/nl/vroste/rezilience/BulkheadSpec.scala
@@ -48,7 +48,7 @@ object BulkheadSpec extends ZIOSpecDefault {
               .foreachParDiscard(1 to max + 2)(_ =>
                 bulkhead(callsCompleted.updateAndGet(_ + 1) *> ZIO.sleep(2.seconds))
               )
-              .withParallelismUnbounded
+              .withParallelism(100)
               .fork
           _                <- TestClock.adjust(1.second)
           nrCallsCompleted <- callsCompleted.get