diff --git a/akka-actor/src/main/scala-2.11/akka/util/ByteIterator.scala b/akka-actor/src/main/scala-2.11/akka/util/ByteIterator.scala
index f877dfec65..e329baeb60 100644
--- a/akka-actor/src/main/scala-2.11/akka/util/ByteIterator.scala
+++ b/akka-actor/src/main/scala-2.11/akka/util/ByteIterator.scala
@@ -460,7 +460,11 @@ abstract class ByteIterator extends BufferedIterator[Byte] {
 
   override def indexWhere(p: Byte => Boolean): Int = indexWhere(p, 0)
   def indexWhere(p: Byte => Boolean, from: Int): Int = {
-    var index = from
+    var index = 0
+    while (index < from) {
+      next()
+      index += 1
+    }
     var found = false
     while (!found && hasNext) if (p(next())) {
       found = true
@@ -471,7 +475,7 @@ abstract class ByteIterator extends BufferedIterator[Byte] {
   }
 
   def indexOf(elem: Byte): Int = indexOf(elem, 0)
-  def indexOf(elem: Byte, from: Int): Int = indexWhere(_ == elem, 0)
+  def indexOf(elem: Byte, from: Int): Int = indexWhere(_ == elem, from)
 
   override def indexOf[B >: Byte](elem: B): Int = indexOf[B](elem, 0)
   def indexOf[B >: Byte](elem: B, from: Int): Int = indexWhere(_ == elem, from)
diff --git a/akka-actor/src/main/scala-2.13+/akka/util/ByteIterator.scala b/akka-actor/src/main/scala-2.13+/akka/util/ByteIterator.scala
index 80e74366e5..48e149b823 100644
--- a/akka-actor/src/main/scala-2.13+/akka/util/ByteIterator.scala
+++ b/akka-actor/src/main/scala-2.13+/akka/util/ByteIterator.scala
@@ -466,7 +466,11 @@ abstract class ByteIterator extends BufferedIterator[Byte] {
   }
 
   override def indexWhere(p: Byte => Boolean, from: Int = 0): Int = {
-    var index = from
+    var index = 0
+    while (index < from) {
+      next()
+      index += 1
+    }
     var found = false
     while (!found && hasNext) if (p(next())) {
       found = true