diff --git a/effect/src/main/scala/korolev/effect/io/FileIO.scala b/effect/src/main/scala/korolev/effect/io/FileIO.scala
index 7b279d86..aba86ad1 100644
--- a/effect/src/main/scala/korolev/effect/io/FileIO.scala
+++ b/effect/src/main/scala/korolev/effect/io/FileIO.scala
@@ -26,7 +26,7 @@ object FileIO {
 
   def readBytes[F[_]: Effect](path: Path): F[LazyBytes[F]] = {
     val inputStream = new FileInputStream(path.toFile)
-    LazyBytes(inputStream)
+    LazyBytes.fromInputStream(inputStream)
   }
 
   def readLines[F[_]: Effect](path: Path): F[Stream[F, String]] = {
diff --git a/effect/src/main/scala/korolev/effect/io/LazyBytes.scala b/effect/src/main/scala/korolev/effect/io/LazyBytes.scala
index 2150bfde..709b8902 100644
--- a/effect/src/main/scala/korolev/effect/io/LazyBytes.scala
+++ b/effect/src/main/scala/korolev/effect/io/LazyBytes.scala
@@ -70,7 +70,7 @@ object LazyBytes {
     new LazyBytes(Stream.eval(bytes), Some(bytes.length.toLong))
   }
 
-  def apply[F[_] : Effect](inputStream: InputStream, chunkSize: Int = 8192): F[LazyBytes[F]] = {
+  def fromInputStream[F[_] : Effect](inputStream: InputStream, chunkSize: Int = 8192): F[LazyBytes[F]] = {
     @tailrec
     def readStream(chunk: Array[Byte], offset: Int, len: Int): (Unit, Option[Array[Byte]]) = {
       val read = inputStream.read(chunk, offset, len)
diff --git a/effect/src/test/scala/korolev/effect/io/LazyBytesSpec.scala b/effect/src/test/scala/korolev/effect/io/LazyBytesSpec.scala
new file mode 100644
index 00000000..91819ea6
--- /dev/null
+++ b/effect/src/test/scala/korolev/effect/io/LazyBytesSpec.scala
@@ -0,0 +1,17 @@
+package korolev.effect.io
+
+import java.io.ByteArrayInputStream
+
+import org.scalatest.{AsyncFlatSpec, Matchers}
+
+class LazyBytesSpec extends AsyncFlatSpec with Matchers {
+
+  final val inputStream1Length = 239978
+  final val inputStream1 = new ByteArrayInputStream(Array.fill[Byte](inputStream1Length)(1))
+
+  "LazyBytes.fromInputStream" should "return exactly same bytes as contains in InputStream" in {
+    LazyBytes.fromInputStream(inputStream1).flatMap(_.toStrict).map { bytes =>
+      bytes.length shouldEqual inputStream1Length
+    }
+  }
+}
diff --git a/interop/akka/src/main/scala/korolev/akka/Converters.scala b/interop/akka/src/main/scala/korolev/akka/Converters.scala
index e6f8d2da..342ead2d 100644
--- a/interop/akka/src/main/scala/korolev/akka/Converters.scala
+++ b/interop/akka/src/main/scala/korolev/akka/Converters.scala
@@ -17,6 +17,7 @@
 package korolev.akka
 
 import akka.NotUsed
+import akka.stream.{Attributes, OverflowStrategy}
 import akka.stream.scaladsl.{Sink, Source}
 import korolev.akka.util.{KorolevStreamPublisher, KorolevStreamSubscriber}
 import korolev.effect.{Effect, Stream}
@@ -59,7 +60,9 @@ object Converters {
 
     def asAkkaSource: Source[T, NotUsed] = {
       val publisher = new KorolevStreamPublisher(stream, fanout = false)
-      Source.fromPublisher(publisher)
+      Source
+        .fromPublisher(publisher)
+        .buffer(10, OverflowStrategy.backpressure) // FIXME should work without this line. Looks like bug in akka-streams
     }
   }
 }
diff --git a/interop/akka/src/main/scala/korolev/akka/util/KorolevStreamPublisher.scala b/interop/akka/src/main/scala/korolev/akka/util/KorolevStreamPublisher.scala
index 4ecd7305..c051a57f 100644
--- a/interop/akka/src/main/scala/korolev/akka/util/KorolevStreamPublisher.scala
+++ b/interop/akka/src/main/scala/korolev/akka/util/KorolevStreamPublisher.scala
@@ -38,6 +38,8 @@ final class KorolevStreamPublisher[F[_] : Effect, T](stream: Stream[F, T],
     @volatile var pending: Effect.Promise[Unit] = _
     val res = Right(())
 
+    def value(): F[Long] = Effect[F].delay(n)
+
     def decOrLock(): F[Unit] = Effect[F].promise[Unit] { cb =>
       this.synchronized { // FIXME use CAS?
         if (n == 0) {
@@ -49,7 +51,7 @@ final class KorolevStreamPublisher[F[_] : Effect, T](stream: Stream[F, T],
       }
     }
 
-    def setUnsafe(x: Long): Unit =
+    def unsafeSet(x: Long): Unit =
       this.synchronized {
         n = x
         if (x > 0 && pending != null) {
@@ -79,10 +81,13 @@ final class KorolevStreamPublisher[F[_] : Effect, T](stream: Stream[F, T],
         }
       } yield ()
 
-    loop().runAsyncForget
+    loop().runAsync {
+      case Left(error) => subscriber.onError(error)
+      case Right(_) => ()
+    }
 
     def request(n: Long): Unit = {
-      counter.setUnsafe(n)
+      counter.unsafeSet(n)
     }
 
     def cancel(): Unit = {
diff --git a/korolev/src/main/scala/korolev/server/internal/services/FilesService.scala b/korolev/src/main/scala/korolev/server/internal/services/FilesService.scala
index f512114d..f12bba35 100644
--- a/korolev/src/main/scala/korolev/server/internal/services/FilesService.scala
+++ b/korolev/src/main/scala/korolev/server/internal/services/FilesService.scala
@@ -41,7 +41,7 @@ private[korolev] final class FilesService[F[_]: Effect](commonService: CommonSer
         case Some(mimeType) => Seq(Headers.ContentType -> mimeType)
         case None           => Nil
       }
-      LazyBytes(javaSyncStream) map { lazyBytes =>
+      LazyBytes.fromInputStream(javaSyncStream) map { lazyBytes =>
         Response(Response.Status.Ok, lazyBytes, headers)
       }
     }