diff --git a/core/src/main/scala/sttp/client4/backend.scala b/core/src/main/scala/sttp/client4/backend.scala
index b61e54b278..77ca89010c 100644
--- a/core/src/main/scala/sttp/client4/backend.scala
+++ b/core/src/main/scala/sttp/client4/backend.scala
@@ -53,9 +53,7 @@ trait SyncBackend extends Backend[Identity] {
 }
 
 /** A [[GenericBackend]] which is synchronous (side effects are run directly), and supports web sockets. */
-trait WebSocketSyncBackend extends SyncBackend with WebSocketBackend[Identity] {
-  override def monad: MonadError[Identity] = IdMonad
-}
+trait WebSocketSyncBackend extends SyncBackend with WebSocketBackend[Identity]
 
 /** A [[GenericBackend]] which supports streams of type `S` and uses `F` to represent side-effects. */
 trait StreamBackend[F[_], +S] extends Backend[F] with GenericBackend[F, S]
diff --git a/core/src/main/scalajvm/sttp/client4/httpclient/HttpClientBackend.scala b/core/src/main/scalajvm/sttp/client4/httpclient/HttpClientBackend.scala
index 077f173a08..d9ce966472 100644
--- a/core/src/main/scalajvm/sttp/client4/httpclient/HttpClientBackend.scala
+++ b/core/src/main/scalajvm/sttp/client4/httpclient/HttpClientBackend.scala
@@ -152,12 +152,12 @@ abstract class HttpClientBackend[F[_], S <: Streams[S], P, B](
     wsBuilder
   }
 
-  private[client4] def filterIllegalWsHeaders[T](request: GenericRequest[T, R]): GenericRequest[T, R] =
+  private def filterIllegalWsHeaders[T](request: GenericRequest[T, R]): GenericRequest[T, R] =
     request.withHeaders(request.headers.filter(h => !wsIllegalHeaders.contains(h.name.toLowerCase)))
 
   // these headers can't be sent using HttpClient; the SecWebSocketProtocol is supported through a builder method,
   // the resit is ignored
-  private[client4] lazy val wsIllegalHeaders: Set[String] = {
+  private lazy val wsIllegalHeaders: Set[String] = {
     import HeaderNames._
     Set(SecWebSocketAccept, SecWebSocketExtensions, SecWebSocketKey, SecWebSocketVersion, SecWebSocketProtocol).map(
       _.toLowerCase
diff --git a/core/src/main/scalajvm/sttp/client4/httpclient/HttpClientSyncBackend.scala b/core/src/main/scalajvm/sttp/client4/httpclient/HttpClientSyncBackend.scala
index 3467212b73..4ec80b2168 100644
--- a/core/src/main/scalajvm/sttp/client4/httpclient/HttpClientSyncBackend.scala
+++ b/core/src/main/scalajvm/sttp/client4/httpclient/HttpClientSyncBackend.scala
@@ -16,7 +16,7 @@ import sttp.client4.internal.httpclient.{
 }
 import sttp.client4.internal.ws.{SimpleQueue, SyncQueue, WebSocketEvent}
 import sttp.client4.monad.IdMonad
-import sttp.client4.testing.{WebSocketBackendStub, WebSocketSyncBackendStub}
+import sttp.client4.testing.WebSocketSyncBackendStub
 import sttp.client4.{wrappers, BackendOptions, GenericRequest, Identity, Response, WebSocketSyncBackend}
 import sttp.model.StatusCode
 import sttp.monad.MonadError
@@ -31,7 +31,6 @@ import java.util.concurrent.{ArrayBlockingQueue, CompletionException}
 import java.util.concurrent.atomic.AtomicBoolean
 import java.util.zip.{GZIPInputStream, InflaterInputStream}
 import scala.concurrent.{blocking, Await, ExecutionContext, Future}
-import scala.util.Try
 
 class HttpClientSyncBackend private (
     client: HttpClient,
@@ -46,6 +45,7 @@ class HttpClientSyncBackend private (
     with WebSocketSyncBackend {
 
   private implicit val ec: ExecutionContext = ExecutionContext.global
+  private implicit def _monad: MonadError[Identity] = monad
   override val streams: NoStreams = NoStreams
 
   override protected def sendRegular[T](request: GenericRequest[T, R]): Identity[Response[T]] = {
@@ -64,7 +64,7 @@ class HttpClientSyncBackend private (
           Left(emptyInputStream()),
           request
         )
-    }(monad)
+    }
   }
 
   private def sendWebSocket[T](
@@ -75,9 +75,9 @@ class HttpClientSyncBackend private (
     val isOpen: AtomicBoolean = new AtomicBoolean(false)
     val responseCell = new ArrayBlockingQueue[Either[Throwable, Future[Response[T]]]](1)
 
-    def fillCellError(t: Throwable): Unit = responseCell.add(Left(t))
+    def fillCellError(t: Throwable): Unit = responseCell.add(Left(t)): Unit
 
-    def fillCell(wr: Future[Response[T]]): Unit = responseCell.add(Right(wr))
+    def fillCell(wr: Future[Response[T]]): Unit = responseCell.add(Right(wr)): Unit
 
     val listener = new DelegatingWebSocketListener(
       new AddToQueueListener(queue, isOpen),
@@ -88,10 +88,7 @@ class HttpClientSyncBackend private (
           isOpen,
           sequencer,
           monad,
-          cf =>
-            monad.suspend {
-              Try(cf.get()).fold(monad.error, _ => monad.unit(()))
-            }
+          _.get(): Unit
         )
         val baseResponse = Response((), StatusCode.SwitchingProtocols, "", Nil, Nil, request.onlyMetadata)
         val body = Future(blocking(bodyFromHttpClient(Right(webSocket), request.response, baseResponse)))
diff --git a/core/src/main/scalajvm/sttp/client4/internal/httpclient/IdSequencer.scala b/core/src/main/scalajvm/sttp/client4/internal/httpclient/IdSequencer.scala
index 35542f7bec..3420f39b89 100644
--- a/core/src/main/scalajvm/sttp/client4/internal/httpclient/IdSequencer.scala
+++ b/core/src/main/scalajvm/sttp/client4/internal/httpclient/IdSequencer.scala
@@ -9,9 +9,7 @@ private[client4] class IdSequencer extends Sequencer[Identity] {
   private val semaphore = new Semaphore(1)
 
   def apply[T](t: => T): T = {
-    blocking {
-      semaphore.acquire()
-    }
+    blocking(semaphore.acquire())
     try t
     finally semaphore.release()
   }
diff --git a/docs/json.md b/docs/json.md
index e1d974cb7c..0a100503b0 100644
--- a/docs/json.md
+++ b/docs/json.md
@@ -163,7 +163,7 @@ import sttp.client4._
 import sttp.client4.ziojson._
 import zio.json._
 
-val backend: WebSocketSyncBackend = DefaultSyncBackend()
+val backend: SyncBackend = DefaultSyncBackend()
 
 implicit val payloadJsonEncoder: JsonEncoder[RequestPayload] = DeriveJsonEncoder.gen[RequestPayload]
 implicit val myResponseJsonDecoder: JsonDecoder[ResponsePayload] = DeriveJsonDecoder.gen[ResponsePayload]