diff --git a/actix-service/src/apply.rs b/actix-service/src/apply.rs
index 2a1b93f3..03b321f8 100644
--- a/actix-service/src/apply.rs
+++ b/actix-service/src/apply.rs
@@ -4,28 +4,31 @@ use std::marker::PhantomData;
 use std::pin::Pin;
 use std::task::{Context, Poll};
 
-use super::IntoFuture;
 use super::{Factory, IntoFactory, IntoService, Service};
 
 /// Apply tranform function to a service
-pub fn apply_fn<T, F, In, Out, U>(service: U, f: F) -> Apply<T, F, In, Out>
+pub fn apply_fn<T, F, R, In, Out, Err, U>(
+    service: U,
+    f: F,
+) -> impl Service<Request = In, Response = Out, Error = Err>
 where
-    T: Service,
-    F: FnMut(In, &mut T) -> Out,
-    Out: IntoFuture,
-    Out::Error: From<T::Error>,
+    T: Service<Error = Err>,
+    F: FnMut(In, &mut T) -> R,
+    R: Future<Output = Result<Out, Err>>,
     U: IntoService<T>,
 {
     Apply::new(service.into_service(), f)
 }
 
 /// Create factory for `apply` service.
-pub fn apply_fn_factory<T, F, In, Out, U>(service: U, f: F) -> ApplyNewService<T, F, In, Out>
+pub fn apply_fn_factory<T, F, R, In, Out, Err, U>(
+    service: U,
+    f: F,
+) -> impl Factory<Request = In, Response = Out, Error = Err>
 where
-    T: Factory,
-    F: FnMut(In, &mut T::Service) -> Out + Clone,
-    Out: IntoFuture,
-    Out::Error: From<T::Error>,
+    T: Factory<Error = Err>,
+    F: FnMut(In, &mut T::Service) -> R + Clone,
+    R: Future<Output = Result<Out, Err>>,
     U: IntoFactory<T>,
 {
     ApplyNewService::new(service.into_factory(), f)
@@ -34,25 +37,24 @@ where
 #[doc(hidden)]
 /// `Apply` service combinator
 #[pin_project]
-pub struct Apply<T, F, In, Out>
+struct Apply<T, F, R, In, Out, Err>
 where
-    T: Service,
+    T: Service<Error = Err>,
 {
     #[pin]
     service: T,
     f: F,
-    r: PhantomData<(In, Out)>,
+    r: PhantomData<(In, Out, R)>,
 }
 
-impl<T, F, In, Out> Apply<T, F, In, Out>
+impl<T, F, R, In, Out, Err> Apply<T, F, R, In, Out, Err>
 where
-    T: Service,
-    F: FnMut(In, &mut T) -> Out,
-    Out: IntoFuture,
-    Out::Error: From<T::Error>,
+    T: Service<Error = Err>,
+    F: FnMut(In, &mut T) -> R,
+    R: Future<Output = Result<Out, Err>>,
 {
     /// Create new `Apply` combinator
-    pub(crate) fn new(service: T, f: F) -> Self {
+    fn new(service: T, f: F) -> Self {
         Self {
             service,
             f,
@@ -61,60 +63,44 @@ where
     }
 }
 
-impl<T, F, In, Out> Clone for Apply<T, F, In, Out>
+impl<T, F, R, In, Out, Err> Service for Apply<T, F, R, In, Out, Err>
 where
-    T: Service + Clone,
-    F: Clone,
-{
-    fn clone(&self) -> Self {
-        Apply {
-            service: self.service.clone(),
-            f: self.f.clone(),
-            r: PhantomData,
-        }
-    }
-}
-
-impl<T, F, In, Out> Service for Apply<T, F, In, Out>
-where
-    T: Service,
-    F: FnMut(In, &mut T) -> Out,
-    Out: IntoFuture,
-    Out::Error: From<T::Error>,
+    T: Service<Error = Err>,
+    F: FnMut(In, &mut T) -> R,
+    R: Future<Output = Result<Out, Err>>,
 {
     type Request = In;
-    type Response = Out::Item;
-    type Error = Out::Error;
-    type Future = Out::Future;
+    type Response = Out;
+    type Error = Err;
+    type Future = R;
 
     fn poll_ready(&mut self, ctx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
-        Poll::Ready(futures::ready!(self.service.poll_ready(ctx)).map_err(|e| e.into()))
+        Poll::Ready(futures::ready!(self.service.poll_ready(ctx)))
     }
 
     fn call(&mut self, req: In) -> Self::Future {
-        (self.f)(req, &mut self.service).into_future()
+        (self.f)(req, &mut self.service)
     }
 }
 
 /// `ApplyNewService` new service combinator
-pub struct ApplyNewService<T, F, In, Out>
+struct ApplyNewService<T, F, R, In, Out, Err>
 where
-    T: Factory,
+    T: Factory<Error = Err>,
 {
     service: T,
     f: F,
-    r: PhantomData<(In, Out)>,
+    r: PhantomData<(R, In, Out)>,
 }
 
-impl<T, F, In, Out> ApplyNewService<T, F, In, Out>
+impl<T, F, R, In, Out, Err> ApplyNewService<T, F, R, In, Out, Err>
 where
-    T: Factory,
-    F: FnMut(In, &mut T::Service) -> Out + Clone,
-    Out: IntoFuture,
-    Out::Error: From<T::Error>,
+    T: Factory<Error = Err>,
+    F: FnMut(In, &mut T::Service) -> R + Clone,
+    R: Future<Output = Result<Out, Err>>,
 {
     /// Create new `ApplyNewService` new service instance
-    pub(crate) fn new(service: T, f: F) -> Self {
+    fn new(service: T, f: F) -> Self {
         Self {
             f,
             service,
@@ -123,36 +109,20 @@ where
     }
 }
 
-impl<T, F, In, Out> Clone for ApplyNewService<T, F, In, Out>
+impl<T, F, R, In, Out, Err> Factory for ApplyNewService<T, F, R, In, Out, Err>
 where
-    T: Factory + Clone,
-    F: FnMut(In, &mut T::Service) -> Out + Clone,
-    Out: IntoFuture,
-{
-    fn clone(&self) -> Self {
-        Self {
-            service: self.service.clone(),
-            f: self.f.clone(),
-            r: PhantomData,
-        }
-    }
-}
-
-impl<T, F, In, Out> Factory for ApplyNewService<T, F, In, Out>
-where
-    T: Factory,
-    F: FnMut(In, &mut T::Service) -> Out + Clone,
-    Out: IntoFuture,
-    Out::Error: From<T::Error>,
+    T: Factory<Error = Err>,
+    F: FnMut(In, &mut T::Service) -> R + Clone,
+    R: Future<Output = Result<Out, Err>>,
 {
     type Request = In;
-    type Response = Out::Item;
-    type Error = Out::Error;
+    type Response = Out;
+    type Error = Err;
 
     type Config = T::Config;
-    type Service = Apply<T::Service, F, In, Out>;
+    type Service = Apply<T::Service, F, R, In, Out, Err>;
     type InitError = T::InitError;
-    type Future = ApplyNewServiceFuture<T, F, In, Out>;
+    type Future = ApplyNewServiceFuture<T, F, R, In, Out, Err>;
 
     fn new_service(&self, cfg: &T::Config) -> Self::Future {
         ApplyNewServiceFuture::new(self.service.new_service(cfg), self.f.clone())
@@ -160,11 +130,11 @@ where
 }
 
 #[pin_project]
-pub struct ApplyNewServiceFuture<T, F, In, Out>
+struct ApplyNewServiceFuture<T, F, R, In, Out, Err>
 where
-    T: Factory,
-    F: FnMut(In, &mut T::Service) -> Out + Clone,
-    Out: IntoFuture,
+    T: Factory<Error = Err>,
+    F: FnMut(In, &mut T::Service) -> R + Clone,
+    R: Future<Output = Result<Out, Err>>,
 {
     #[pin]
     fut: T::Future,
@@ -172,11 +142,11 @@ where
     r: PhantomData<(In, Out)>,
 }
 
-impl<T, F, In, Out> ApplyNewServiceFuture<T, F, In, Out>
+impl<T, F, R, In, Out, Err> ApplyNewServiceFuture<T, F, R, In, Out, Err>
 where
-    T: Factory,
-    F: FnMut(In, &mut T::Service) -> Out + Clone,
-    Out: IntoFuture,
+    T: Factory<Error = Err>,
+    F: FnMut(In, &mut T::Service) -> R + Clone,
+    R: Future<Output = Result<Out, Err>>,
 {
     fn new(fut: T::Future, f: F) -> Self {
         ApplyNewServiceFuture {
@@ -187,14 +157,13 @@ where
     }
 }
 
-impl<T, F, In, Out> Future for ApplyNewServiceFuture<T, F, In, Out>
+impl<T, F, R, In, Out, Err> Future for ApplyNewServiceFuture<T, F, R, In, Out, Err>
 where
-    T: Factory,
-    F: FnMut(In, &mut T::Service) -> Out + Clone,
-    Out: IntoFuture,
-    Out::Error: From<T::Error>,
+    T: Factory<Error = Err>,
+    F: FnMut(In, &mut T::Service) -> R + Clone,
+    R: Future<Output = Result<Out, Err>>,
 {
-    type Output = Result<Apply<T::Service, F, In, Out>, T::InitError>;
+    type Output = Result<Apply<T::Service, F, R, In, Out, Err>, T::InitError>;
 
     fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
         let this = self.project();
diff --git a/actix-service/src/apply_cfg.rs b/actix-service/src/apply_cfg.rs
index 5a79d766..cd6a62f1 100644
--- a/actix-service/src/apply_cfg.rs
+++ b/actix-service/src/apply_cfg.rs
@@ -7,10 +7,10 @@ use futures::ready;
 use pin_project::pin_project;
 
 use crate::cell::Cell;
-use crate::{Factory, IntoFuture, IntoService, Service};
+use crate::{Factory, IntoService, Service};
 
 /// Convert `Fn(&Config, &mut Service) -> Future<Service>` fn to a NewService
-pub fn apply_cfg<F, C, T, R, S>(
+pub fn apply_cfg<F, C, T, R, S, E>(
     srv: T,
     f: F,
 ) -> impl Factory<
@@ -19,18 +19,17 @@ pub fn apply_cfg<F, C, T, R, S>(
     Response = S::Response,
     Error = S::Error,
     Service = S,
-    InitError = R::Error,
+    InitError = E,
 > + Clone
 where
     F: FnMut(&C, &mut T) -> R,
     T: Service,
-    R: IntoFuture,
-    R::Item: IntoService<S>,
+    R: Future<Output = Result<S, E>>,
     S: Service,
 {
     ApplyConfigService {
         f: Cell::new(f),
-        srv: Cell::new(srv.into_service()),
+        srv: Cell::new(srv),
         _t: PhantomData,
     }
 }
@@ -53,8 +52,7 @@ where
     F: FnMut(&C, &mut T::Service) -> R,
     T: Factory<Config = ()>,
     T::InitError: From<T::Error>,
-    R: IntoFuture<Error = T::InitError>,
-    R::Item: IntoService<S>,
+    R: Future<Output = Result<S, T::InitError>>,
     S: Service,
 {
     ApplyConfigNewService {
@@ -66,12 +64,11 @@ where
 
 /// Convert `Fn(&Config) -> Future<Service>` fn to NewService\
 #[pin_project]
-struct ApplyConfigService<F, C, T, R, S>
+struct ApplyConfigService<F, C, T, R, S, E>
 where
     F: FnMut(&C, &mut T) -> R,
     T: Service,
-    R: IntoFuture,
-    R::Item: IntoService<S>,
+    R: Future<Output = Result<S, E>>,
     S: Service,
 {
     f: Cell<F>,
@@ -80,12 +77,11 @@ where
     _t: PhantomData<(C, R, S)>,
 }
 
-impl<F, C, T, R, S> Clone for ApplyConfigService<F, C, T, R, S>
+impl<F, C, T, R, S, E> Clone for ApplyConfigService<F, C, T, R, S, E>
 where
     F: FnMut(&C, &mut T) -> R,
     T: Service,
-    R: IntoFuture,
-    R::Item: IntoService<S>,
+    R: Future<Output = Result<S, E>>,
     S: Service,
 {
     fn clone(&self) -> Self {
@@ -97,12 +93,11 @@ where
     }
 }
 
-impl<F, C, T, R, S> Factory for ApplyConfigService<F, C, T, R, S>
+impl<F, C, T, R, S, E> Factory for ApplyConfigService<F, C, T, R, S, E>
 where
     F: FnMut(&C, &mut T) -> R,
     T: Service,
-    R: IntoFuture,
-    R::Item: IntoService<S>,
+    R: Future<Output = Result<S, E>>,
     S: Service,
 {
     type Config = C;
@@ -111,37 +106,34 @@ where
     type Error = S::Error;
     type Service = S;
 
-    type InitError = R::Error;
-    type Future = FnNewServiceConfigFut<R, S>;
+    type InitError = E;
+    type Future = FnNewServiceConfigFut<R, S, E>;
 
     fn new_service(&self, cfg: &C) -> Self::Future {
         FnNewServiceConfigFut {
-            fut: unsafe { (self.f.get_mut_unsafe())(cfg, self.srv.get_mut_unsafe()) }
-                .into_future(),
+            fut: unsafe { (self.f.get_mut_unsafe())(cfg, self.srv.get_mut_unsafe()) },
             _t: PhantomData,
         }
     }
 }
 
 #[pin_project]
-struct FnNewServiceConfigFut<R, S>
+struct FnNewServiceConfigFut<R, S, E>
 where
-    R: IntoFuture,
-    R::Item: IntoService<S>,
+    R: Future<Output = Result<S, E>>,
     S: Service,
 {
     #[pin]
-    fut: R::Future,
+    fut: R,
     _t: PhantomData<(S,)>,
 }
 
-impl<R, S> Future for FnNewServiceConfigFut<R, S>
+impl<R, S, E> Future for FnNewServiceConfigFut<R, S, E>
 where
-    R: IntoFuture,
-    R::Item: IntoService<S>,
+    R: Future<Output = Result<S, E>>,
     S: Service,
 {
-    type Output = Result<S, R::Error>;
+    type Output = Result<S, E>;
 
     fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
         Poll::Ready(Ok(ready!(self.project().fut.poll(cx))?.into_service()))
@@ -154,8 +146,7 @@ where
     C: Clone,
     F: FnMut(&C, &mut T::Service) -> R,
     T: Factory<Config = ()>,
-    R: IntoFuture<Error = T::InitError>,
-    R::Item: IntoService<S>,
+    R: Future<Output = Result<S, T::InitError>>,
     S: Service,
 {
     f: Cell<F>,
@@ -168,8 +159,7 @@ where
     C: Clone,
     F: FnMut(&C, &mut T::Service) -> R,
     T: Factory<Config = ()>,
-    R: IntoFuture<Error = T::InitError>,
-    R::Item: IntoService<S>,
+    R: Future<Output = Result<S, T::InitError>>,
     S: Service,
 {
     fn clone(&self) -> Self {
@@ -187,8 +177,7 @@ where
     F: FnMut(&C, &mut T::Service) -> R,
     T: Factory<Config = ()>,
     T::InitError: From<T::Error>,
-    R: IntoFuture<Error = T::InitError>,
-    R::Item: IntoService<S>,
+    R: Future<Output = Result<S, T::InitError>>,
     S: Service,
 {
     type Config = C;
@@ -197,7 +186,7 @@ where
     type Error = S::Error;
     type Service = S;
 
-    type InitError = R::Error;
+    type InitError = T::InitError;
     type Future = ApplyConfigNewServiceFut<F, C, T, R, S>;
 
     fn new_service(&self, cfg: &C) -> Self::Future {
@@ -219,8 +208,7 @@ where
     F: FnMut(&C, &mut T::Service) -> R,
     T: Factory<Config = ()>,
     T::InitError: From<T::Error>,
-    R: IntoFuture<Error = T::InitError>,
-    R::Item: IntoService<S>,
+    R: Future<Output = Result<S, T::InitError>>,
     S: Service,
 {
     cfg: C,
@@ -229,7 +217,7 @@ where
     #[pin]
     srv_fut: Option<T::Future>,
     #[pin]
-    fut: Option<R::Future>,
+    fut: Option<R>,
     _t: PhantomData<(S,)>,
 }
 
@@ -239,11 +227,10 @@ where
     F: FnMut(&C, &mut T::Service) -> R,
     T: Factory<Config = ()>,
     T::InitError: From<T::Error>,
-    R: IntoFuture<Error = T::InitError>,
-    R::Item: IntoService<S>,
+    R: Future<Output = Result<S, T::InitError>>,
     S: Service,
 {
-    type Output = Result<S, R::Error>;
+    type Output = Result<S, T::InitError>;
 
     fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
         let mut this = self.project();
@@ -264,8 +251,7 @@ where
             } else if let Some(ref mut srv) = this.srv {
                 match srv.poll_ready(cx)? {
                     Poll::Ready(_) => {
-                        this.fut
-                            .set(Some(this.f.get_mut()(&this.cfg, srv).into_future()));
+                        this.fut.set(Some(this.f.get_mut()(&this.cfg, srv)));
                         continue 'poll;
                     }
                     Poll::Pending => return Poll::Pending,
diff --git a/actix-service/src/boxed.rs b/actix-service/src/boxed.rs
index 784678a2..e93c7aa4 100644
--- a/actix-service/src/boxed.rs
+++ b/actix-service/src/boxed.rs
@@ -7,7 +7,7 @@ use std::task::{Context, Poll};
 use futures::future::{err, ok, Either, Ready};
 use futures::future::{FutureExt, LocalBoxFuture};
 
-use crate::{Factory, IntoFuture, Service};
+use crate::{Factory, Service};
 
 pub type BoxedService<Req, Res, Err> = Box<
     dyn Service<
diff --git a/actix-service/src/fn_service.rs b/actix-service/src/fn_service.rs
index 743a835b..78c73fe0 100644
--- a/actix-service/src/fn_service.rs
+++ b/actix-service/src/fn_service.rs
@@ -6,163 +6,154 @@ use std::task::{Context, Poll};
 use futures::future::{ok, Ready};
 use pin_project::pin_project;
 
-use crate::IntoFuture;
 use crate::{Factory, IntoFactory, IntoService, Service};
 
-/// Create `NewService` for function that can act as a Service
-pub fn service_fn<F, Req, Out, Cfg>(
+/// Create `Factory` for function that can act as a Service
+pub fn service_fn<F, Fut, Req, Res, Err, Cfg>(
     f: F,
-) -> impl Factory<
-    Config = Cfg,
-    Request = Req,
-    Response = Out::Item,
-    Error = Out::Error,
-    InitError = (),
->
+) -> impl Factory<Config = Cfg, Request = Req, Response = Res, Error = Err, InitError = ()> + Clone
 where
-    F: FnMut(Req) -> Out + Clone,
-    Out: IntoFuture,
+    F: FnMut(Req) -> Fut + Clone,
+    Fut: Future<Output = Result<Res, Err>>,
 {
     NewServiceFn::new(f)
 }
 
 /// Create `Factory` for function that can produce services
-pub fn factory_fn<F, C, R, S, E>(
+pub fn service_fn_factory<S, F, Cfg, Fut, Err>(
     f: F,
 ) -> impl Factory<
-    Config = C,
+    Config = Cfg,
     Request = S::Request,
     Response = S::Response,
     Error = S::Error,
-    InitError = E,
-    Future = R::Future,
+    InitError = Err,
+    Future = Fut,
 >
 where
-    F: Fn() -> R,
-    R: IntoFuture<Item = S, Error = E>,
-    R::Item: IntoService<S>,
     S: Service,
+    F: Fn() -> Fut,
+    Fut: Future<Output = Result<S, Err>>,
 {
     FnNewServiceNoConfig::new(f)
 }
 
-/// Create `NewService` for function that can produce services with configuration
-pub fn new_service_cfg<F, C, R, S, E>(
+/// Create `Factory` for function that can produce services with configuration
+pub fn service_fn_config<F, Fut, Cfg, Srv, Err>(
     f: F,
 ) -> impl Factory<
-    Config = C,
-    Request = S::Request,
-    Response = S::Response,
-    Error = S::Error,
-    InitError = E,
+    Config = Cfg,
+    Request = Srv::Request,
+    Response = Srv::Response,
+    Error = Srv::Error,
+    InitError = Err,
 >
 where
-    F: Fn(&C) -> R,
-    R: IntoFuture<Error = E>,
-    R::Item: IntoService<S>,
-    S: Service,
+    F: Fn(&Cfg) -> Fut,
+    Fut: Future<Output = Result<Srv, Err>>,
+    Srv: Service,
 {
     FnNewServiceConfig::new(f)
 }
 
-pub(crate) struct ServiceFn<F, Req, Out>
+pub struct ServiceFn<F, Fut, Req, Res, Err>
 where
-    F: FnMut(Req) -> Out,
-    Out: IntoFuture,
+    F: FnMut(Req) -> Fut,
+    Fut: Future<Output = Result<Res, Err>>,
 {
     f: F,
     _t: PhantomData<Req>,
 }
 
-impl<F, Req, Out> ServiceFn<F, Req, Out>
+impl<F, Fut, Req, Res, Err> ServiceFn<F, Fut, Req, Res, Err>
 where
-    F: FnMut(Req) -> Out,
-    Out: IntoFuture,
+    F: FnMut(Req) -> Fut,
+    Fut: Future<Output = Result<Res, Err>>,
 {
     pub(crate) fn new(f: F) -> Self {
         ServiceFn { f, _t: PhantomData }
     }
 }
 
-impl<F, Req, Out> Clone for ServiceFn<F, Req, Out>
+impl<F, Fut, Req, Res, Err> Clone for ServiceFn<F, Fut, Req, Res, Err>
 where
-    F: FnMut(Req) -> Out + Clone,
-    Out: IntoFuture,
+    F: FnMut(Req) -> Fut + Clone,
+    Fut: Future<Output = Result<Res, Err>>,
 {
     fn clone(&self) -> Self {
         ServiceFn::new(self.f.clone())
     }
 }
 
-impl<F, Req, Out> Service for ServiceFn<F, Req, Out>
+impl<F, Fut, Req, Res, Err> Service for ServiceFn<F, Fut, Req, Res, Err>
 where
-    F: FnMut(Req) -> Out,
-    Out: IntoFuture,
+    F: FnMut(Req) -> Fut + Clone,
+    Fut: Future<Output = Result<Res, Err>>,
 {
     type Request = Req;
-    type Response = Out::Item;
-    type Error = Out::Error;
-    type Future = Out::Future;
+    type Response = Res;
+    type Error = Err;
+    type Future = Fut;
 
     fn poll_ready(&mut self, _ctx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
         Poll::Ready(Ok(()))
     }
 
     fn call(&mut self, req: Req) -> Self::Future {
-        (self.f)(req).into_future()
+        (self.f)(req)
     }
 }
 
-impl<F, Req, Out> IntoService<ServiceFn<F, Req, Out>> for F
+impl<F, Fut, Req, Res, Err> IntoService<ServiceFn<F, Fut, Req, Res, Err>> for F
 where
-    F: FnMut(Req) -> Out,
-    Out: IntoFuture,
+    F: FnMut(Req) -> Fut + Clone,
+    Fut: Future<Output = Result<Res, Err>>,
 {
-    fn into_service(self) -> ServiceFn<F, Req, Out> {
+    fn into_service(self) -> ServiceFn<F, Fut, Req, Res, Err> {
         ServiceFn::new(self)
     }
 }
 
-pub(crate) struct NewServiceFn<F, Req, Out, Cfg>
+struct NewServiceFn<F, Fut, Req, Res, Err, Cfg>
 where
-    F: FnMut(Req) -> Out,
-    Out: IntoFuture,
+    F: FnMut(Req) -> Fut,
+    Fut: Future<Output = Result<Res, Err>>,
 {
     f: F,
     _t: PhantomData<(Req, Cfg)>,
 }
 
-impl<F, Req, Out, Cfg> NewServiceFn<F, Req, Out, Cfg>
+impl<F, Fut, Req, Res, Err, Cfg> NewServiceFn<F, Fut, Req, Res, Err, Cfg>
 where
-    F: FnMut(Req) -> Out + Clone,
-    Out: IntoFuture,
+    F: FnMut(Req) -> Fut + Clone,
+    Fut: Future<Output = Result<Res, Err>>,
 {
-    pub(crate) fn new(f: F) -> Self {
+    fn new(f: F) -> Self {
         NewServiceFn { f, _t: PhantomData }
     }
 }
 
-impl<F, Req, Out, Cfg> Clone for NewServiceFn<F, Req, Out, Cfg>
+impl<F, Fut, Req, Res, Err, Cfg> Clone for NewServiceFn<F, Fut, Req, Res, Err, Cfg>
 where
-    F: FnMut(Req) -> Out + Clone,
-    Out: IntoFuture,
+    F: FnMut(Req) -> Fut + Clone,
+    Fut: Future<Output = Result<Res, Err>>,
 {
     fn clone(&self) -> Self {
         NewServiceFn::new(self.f.clone())
     }
 }
 
-impl<F, Req, Out, Cfg> Factory for NewServiceFn<F, Req, Out, Cfg>
+impl<F, Fut, Req, Res, Err, Cfg> Factory for NewServiceFn<F, Fut, Req, Res, Err, Cfg>
 where
-    F: FnMut(Req) -> Out + Clone,
-    Out: IntoFuture,
+    F: FnMut(Req) -> Fut + Clone,
+    Fut: Future<Output = Result<Res, Err>>,
 {
     type Request = Req;
-    type Response = Out::Item;
-    type Error = Out::Error;
+    type Response = Res;
+    type Error = Err;
 
     type Config = Cfg;
-    type Service = ServiceFn<F, Req, Out>;
+    type Service = ServiceFn<F, Fut, Req, Res, Err>;
     type InitError = ();
     type Future = Ready<Result<Self::Service, Self::InitError>>;
 
@@ -171,118 +162,79 @@ where
     }
 }
 
-impl<F, Req, Out, Cfg> IntoService<ServiceFn<F, Req, Out>> for NewServiceFn<F, Req, Out, Cfg>
-where
-    F: FnMut(Req) -> Out + Clone,
-    Out: IntoFuture,
-{
-    fn into_service(self) -> ServiceFn<F, Req, Out> {
-        ServiceFn::new(self.f.clone())
-    }
-}
-
-impl<F, Req, Out, Cfg> IntoFactory<NewServiceFn<F, Req, Out, Cfg>> for F
-where
-    F: Fn(Req) -> Out + Clone,
-    Out: IntoFuture,
-{
-    fn into_factory(self) -> NewServiceFn<F, Req, Out, Cfg> {
-        NewServiceFn::new(self)
-    }
-}
-
 /// Convert `Fn(&Config) -> Future<Service>` fn to NewService
-pub(crate) struct FnNewServiceConfig<F, C, R, S, E>
+struct FnNewServiceConfig<F, Fut, Cfg, Srv, Err>
 where
-    F: Fn(&C) -> R,
-    R: IntoFuture<Error = E>,
-    R::Item: IntoService<S>,
-    S: Service,
+    F: Fn(&Cfg) -> Fut,
+    Fut: Future<Output = Result<Srv, Err>>,
+    Srv: Service,
 {
     f: F,
-    _t: PhantomData<(C, R, S, E)>,
+    _t: PhantomData<(Fut, Cfg, Srv, Err)>,
 }
 
-impl<F, C, R, S, E> FnNewServiceConfig<F, C, R, S, E>
+impl<F, Fut, Cfg, Srv, Err> FnNewServiceConfig<F, Fut, Cfg, Srv, Err>
 where
-    F: Fn(&C) -> R,
-    R: IntoFuture<Error = E>,
-    R::Item: IntoService<S>,
-    S: Service,
+    F: Fn(&Cfg) -> Fut,
+    Fut: Future<Output = Result<Srv, Err>>,
+    Srv: Service,
 {
     pub fn new(f: F) -> Self {
         FnNewServiceConfig { f, _t: PhantomData }
     }
 }
 
-impl<F, C, R, S, E> Factory for FnNewServiceConfig<F, C, R, S, E>
+impl<F, Fut, Cfg, Srv, Err> Factory for FnNewServiceConfig<F, Fut, Cfg, Srv, Err>
 where
-    F: Fn(&C) -> R,
-    R: IntoFuture<Error = E>,
-    R::Item: IntoService<S>,
-    S: Service,
+    F: Fn(&Cfg) -> Fut,
+    Fut: Future<Output = Result<Srv, Err>>,
+    Srv: Service,
 {
-    type Request = S::Request;
-    type Response = S::Response;
-    type Error = S::Error;
+    type Request = Srv::Request;
+    type Response = Srv::Response;
+    type Error = Srv::Error;
 
-    type Config = C;
-    type Service = S;
-    type InitError = E;
-    type Future = FnNewServiceConfigFut<R, S, E>;
+    type Config = Cfg;
+    type Service = Srv;
+    type InitError = Err;
+    type Future = FnNewServiceConfigFut<Fut, Srv, Err>;
 
-    fn new_service(&self, cfg: &C) -> Self::Future {
+    fn new_service(&self, cfg: &Cfg) -> Self::Future {
         FnNewServiceConfigFut {
-            fut: (self.f)(cfg).into_future(),
+            fut: (self.f)(cfg),
             _t: PhantomData,
         }
     }
 }
 
 #[pin_project]
-pub(crate) struct FnNewServiceConfigFut<R, S, E>
+struct FnNewServiceConfigFut<R, S, E>
 where
-    R: IntoFuture<Error = E>,
-    R::Item: IntoService<S>,
+    R: Future<Output = Result<S, E>>,
     S: Service,
 {
     #[pin]
-    fut: R::Future,
+    fut: R,
     _t: PhantomData<(S,)>,
 }
 
 impl<R, S, E> Future for FnNewServiceConfigFut<R, S, E>
 where
-    R: IntoFuture<Error = E>,
-    R::Item: IntoService<S>,
+    R: Future<Output = Result<S, E>>,
     S: Service,
 {
-    type Output = Result<S, R::Error>;
+    type Output = Result<S, E>;
 
     fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-        Poll::Ready(Ok(
-            futures::ready!(self.project().fut.poll(cx))?.into_service()
-        ))
-    }
-}
-
-impl<F, C, R, S, E> Clone for FnNewServiceConfig<F, C, R, S, E>
-where
-    F: Fn(&C) -> R + Clone,
-    R: IntoFuture<Error = E>,
-    R::Item: IntoService<S>,
-    S: Service,
-{
-    fn clone(&self) -> Self {
-        Self::new(self.f.clone())
+        Poll::Ready(Ok(futures::ready!(self.project().fut.poll(cx))?))
     }
 }
 
 /// Converter for `Fn() -> Future<Service>` fn
-pub(crate) struct FnNewServiceNoConfig<F, C, R, S, E>
+pub struct FnNewServiceNoConfig<F, C, R, S, E>
 where
     F: Fn() -> R,
-    R: IntoFuture<Item = S, Error = E>,
+    R: Future<Output = Result<S, E>>,
     S: Service,
 {
     f: F,
@@ -292,10 +244,10 @@ where
 impl<F, C, R, S, E> FnNewServiceNoConfig<F, C, R, S, E>
 where
     F: Fn() -> R,
-    R: IntoFuture<Item = S, Error = E>,
+    R: Future<Output = Result<S, E>>,
     S: Service,
 {
-    pub fn new(f: F) -> Self {
+    fn new(f: F) -> Self {
         FnNewServiceNoConfig { f, _t: PhantomData }
     }
 }
@@ -303,7 +255,7 @@ where
 impl<F, C, R, S, E> Factory for FnNewServiceNoConfig<F, C, R, S, E>
 where
     F: Fn() -> R,
-    R: IntoFuture<Item = S, Error = E>,
+    R: Future<Output = Result<S, E>>,
     S: Service,
 {
     type Request = S::Request;
@@ -312,17 +264,17 @@ where
     type Service = S;
     type Config = C;
     type InitError = E;
-    type Future = R::Future;
+    type Future = R;
 
     fn new_service(&self, _: &C) -> Self::Future {
-        (self.f)().into_future()
+        (self.f)()
     }
 }
 
 impl<F, C, R, S, E> Clone for FnNewServiceNoConfig<F, C, R, S, E>
 where
     F: Fn() -> R + Clone,
-    R: IntoFuture<Item = S, Error = E>,
+    R: Future<Output = Result<S, E>>,
     S: Service,
 {
     fn clone(&self) -> Self {
@@ -333,7 +285,7 @@ where
 impl<F, C, R, S, E> IntoFactory<FnNewServiceNoConfig<F, C, R, S, E>> for F
 where
     F: Fn() -> R,
-    R: IntoFuture<Item = S, Error = E>,
+    R: Future<Output = Result<S, E>>,
     S: Service,
 {
     fn into_factory(self) -> FnNewServiceNoConfig<F, C, R, S, E> {
diff --git a/actix-service/src/lib.rs b/actix-service/src/lib.rs
index db5673f7..a79f6ebe 100644
--- a/actix-service/src/lib.rs
+++ b/actix-service/src/lib.rs
@@ -22,29 +22,12 @@ mod transform_err;
 
 pub use self::apply::{apply_fn, apply_fn_factory};
 pub use self::apply_cfg::{apply_cfg, apply_cfg_factory};
-pub use self::fn_service::{factory_fn, new_service_cfg, service_fn};
+pub use self::fn_service::{service_fn, service_fn_config, service_fn_factory};
 pub use self::into::{into_factory, into_service, FactoryMapper, ServiceMapper};
 pub use self::map_config::{map_config, unit_config, MappedConfig};
 pub use self::pipeline::{pipeline, pipeline_factory, Pipeline, PipelineFactory};
 pub use self::transform::{apply_transform, IntoTransform, Transform};
 
-pub trait IntoFuture {
-    type Item;
-    type Error;
-    type Future: Future<Output = Result<Self::Item, Self::Error>>;
-    fn into_future(self) -> Self::Future;
-}
-
-impl<F: Future<Output = Result<I, E>>, I, E> IntoFuture for F {
-    type Item = I;
-    type Error = E;
-    type Future = F;
-
-    fn into_future(self) -> Self::Future {
-        self
-    }
-}
-
 /// An asynchronous function from `Request` to a `Response`.
 pub trait Service {
     /// Requests handled by the service.
@@ -80,31 +63,6 @@ pub trait Service {
     /// Calling `call` without calling `poll_ready` is permitted. The
     /// implementation must be resilient to this fact.
     fn call(&mut self, req: Self::Request) -> Self::Future;
-
-    // #[cfg(test)]
-    // fn poll_test(&mut self) -> Poll<Result<(), Self::Error>> {
-    //     // kinda stupid method, but works for our test purposes
-    //     unsafe {
-    //         let mut this = Pin::new_unchecked(self);
-    //         tokio::runtime::current_thread::Builder::new()
-    //             .build()
-    //             .unwrap()
-    //             .block_on(futures::future::poll_fn(move |cx| {
-    //                 let this = &mut this;
-    //                 Poll::Ready(this.as_mut().poll_ready(cx))
-    //             }))
-    //     }
-    // }
-
-    // fn poll_once<'a>(&'a mut self) -> LocalBoxFuture<'a, Poll<Result<(), Self::Error>>> {
-    //     unsafe {
-    //         let mut this = Pin::new_unchecked(self);
-    //         Pin::new_unchecked(Box::new(futures::future::poll_fn(move |cx| {
-    //             //let this = &mut this;
-    //             Poll::Ready(this.get_unchecked_mut().poll_ready(cx))
-    //         })))
-    //     }
-    // }
 }
 
 /// Creates new `Service` values.
@@ -243,7 +201,7 @@ where
     fn into_service(self) -> T;
 }
 
-/// Trait for types that can be converted to a `ServiceFactory`
+/// Trait for types that can be converted to a `Factory`
 pub trait IntoFactory<T>
 where
     T: Factory,
diff --git a/actix-service/src/map_config.rs b/actix-service/src/map_config.rs
index 912a30bd..e1cfbecc 100644
--- a/actix-service/src/map_config.rs
+++ b/actix-service/src/map_config.rs
@@ -9,7 +9,7 @@ pub enum MappedConfig<'a, T> {
 
 /// Adapt external config to a config for provided new service
 pub fn map_config<T, F, C>(
-    new_service: T,
+    factory: T,
     f: F,
 ) -> impl Factory<
     Config = C,
@@ -22,7 +22,7 @@ where
     T: Factory,
     F: Fn(&C) -> MappedConfig<T::Config>,
 {
-    MapConfig::new(new_service, f)
+    MapConfig::new(factory, f)
 }
 
 /// Replace config with unit