diff --git a/akka-actor/src/main/scala/akka/util/ByteString.scala b/akka-actor/src/main/scala/akka/util/ByteString.scala
index fd1f01dbd0..09694346a2 100644
--- a/akka-actor/src/main/scala/akka/util/ByteString.scala
+++ b/akka-actor/src/main/scala/akka/util/ByteString.scala
@@ -98,7 +98,6 @@ final class ByteString private (bytes: Array[Byte], startIndex: Int, endIndex: I
   override def slice(from: Int, until: Int): ByteString = {
     val newStartIndex = math.max(from, 0) + startIndex
     val newEndIndex = math.min(until, length) + startIndex
-    val newLength = math.max(newEndIndex - newStartIndex, 0)
     if (newEndIndex - newStartIndex <= 0) ByteString.empty
     else new ByteString(bytes, newStartIndex, newEndIndex)
   }