diff --git a/actix-files/src/lib.rs b/actix-files/src/lib.rs
index 3ac176193..07fc00631 100644
--- a/actix-files/src/lib.rs
+++ b/actix-files/src/lib.rs
@@ -16,12 +16,12 @@ use percent_encoding::{utf8_percent_encode, DEFAULT_ENCODE_SET};
 use v_htmlescape::escape as escape_html_entity;
 
 use actix_service::{boxed::BoxedNewService, NewService, Service};
-use actix_web::dev::{CpuFuture, HttpServiceFactory, ResourceDef, ServiceConfig};
-use actix_web::error::{BlockingError, Error, ErrorInternalServerError};
-use actix_web::{
-    web, FromRequest, HttpRequest, HttpResponse, Responder, ServiceFromRequest,
+use actix_web::dev::{
+    CpuFuture, HttpServiceFactory, ResourceDef, ServiceConfig, ServiceFromRequest,
     ServiceRequest, ServiceResponse,
 };
+use actix_web::error::{BlockingError, Error, ErrorInternalServerError};
+use actix_web::{web, FromRequest, HttpRequest, HttpResponse, Responder};
 use futures::future::{ok, FutureResult};
 
 mod config;
@@ -34,7 +34,8 @@ pub use crate::config::{DefaultConfig, StaticFileConfig};
 pub use crate::named::NamedFile;
 pub use crate::range::HttpRange;
 
-type HttpNewService<P> = BoxedNewService<(), ServiceRequest<P>, ServiceResponse, (), ()>;
+type HttpNewService<P> =
+    BoxedNewService<(), ServiceRequest<P>, ServiceResponse, Error, ()>;
 
 /// Return the MIME type associated with a filename extension (case-insensitive).
 /// If `ext` is empty or no associated type for the extension was found, returns
@@ -319,7 +320,7 @@ where
 impl<P, C: StaticFileConfig + 'static> NewService for Files<P, C> {
     type Request = ServiceRequest<P>;
     type Response = ServiceResponse;
-    type Error = ();
+    type Error = Error;
     type Service = FilesService<P, C>;
     type InitError = ();
     type Future = FutureResult<Self::Service, Self::InitError>;
@@ -352,7 +353,7 @@ pub struct FilesService<S, C = DefaultConfig> {
 impl<P, C: StaticFileConfig> Service for FilesService<P, C> {
     type Request = ServiceRequest<P>;
     type Response = ServiceResponse;
-    type Error = ();
+    type Error = Error;
     type Future = FutureResult<Self::Response, Self::Error>;
 
     fn poll_ready(&mut self) -> Poll<(), Self::Error> {
diff --git a/actix-session/src/cookie.rs b/actix-session/src/cookie.rs
index e25031456..37c552ea8 100644
--- a/actix-session/src/cookie.rs
+++ b/actix-session/src/cookie.rs
@@ -19,8 +19,9 @@ use std::collections::HashMap;
 use std::rc::Rc;
 
 use actix_service::{Service, Transform};
+use actix_web::dev::{ServiceRequest, ServiceResponse};
 use actix_web::http::{header::SET_COOKIE, HeaderValue};
-use actix_web::{Error, HttpMessage, ResponseError, ServiceRequest, ServiceResponse};
+use actix_web::{Error, HttpMessage, ResponseError};
 use cookie::{Cookie, CookieJar, Key, SameSite};
 use derive_more::{Display, From};
 use futures::future::{ok, Future, FutureResult};
diff --git a/actix-session/src/lib.rs b/actix-session/src/lib.rs
index 79b7e1f9c..1dd367ba7 100644
--- a/actix-session/src/lib.rs
+++ b/actix-session/src/lib.rs
@@ -45,8 +45,8 @@
 use std::cell::RefCell;
 use std::rc::Rc;
 
+use actix_web::dev::{ServiceFromRequest, ServiceRequest, ServiceResponse};
 use actix_web::{Error, FromRequest, HttpMessage};
-use actix_web::{ServiceFromRequest, ServiceRequest, ServiceResponse};
 use hashbrown::HashMap;
 use serde::de::DeserializeOwned;
 use serde::Serialize;
diff --git a/src/extract/mod.rs b/src/extract/mod.rs
index 78c6ba790..25a046d47 100644
--- a/src/extract/mod.rs
+++ b/src/extract/mod.rs
@@ -40,7 +40,7 @@ pub trait FromRequest<P>: Sized {
 ///
 /// ```rust
 /// # #[macro_use] extern crate serde_derive;
-/// use actix_web::{web, App, Error, FromRequest, ServiceFromRequest};
+/// use actix_web::{web, dev, App, Error, FromRequest};
 /// use actix_web::error::ErrorBadRequest;
 /// use rand;
 ///
@@ -53,7 +53,7 @@ pub trait FromRequest<P>: Sized {
 ///     type Error = Error;
 ///     type Future = Result<Self, Self::Error>;
 ///
-///     fn from_request(req: &mut ServiceFromRequest<P>) -> Self::Future {
+///     fn from_request(req: &mut dev::ServiceFromRequest<P>) -> Self::Future {
 ///         if rand::random() {
 ///             Ok(Thing { name: "thingy".into() })
 ///         } else {
@@ -107,7 +107,7 @@ where
 ///
 /// ```rust
 /// # #[macro_use] extern crate serde_derive;
-/// use actix_web::{web, App, Result, Error, FromRequest, ServiceFromRequest};
+/// use actix_web::{web, dev, App, Result, Error, FromRequest};
 /// use actix_web::error::ErrorBadRequest;
 /// use rand;
 ///
@@ -120,7 +120,7 @@ where
 ///     type Error = Error;
 ///     type Future = Result<Thing, Error>;
 ///
-///     fn from_request(req: &mut ServiceFromRequest<P>) -> Self::Future {
+///     fn from_request(req: &mut dev::ServiceFromRequest<P>) -> Self::Future {
 ///         if rand::random() {
 ///             Ok(Thing { name: "thingy".into() })
 ///         } else {