diff --git a/src/app.rs b/src/app.rs
index fdedb0a7..6a4b97b6 100644
--- a/src/app.rs
+++ b/src/app.rs
@@ -459,8 +459,8 @@ where
 {
     fn into_factory(self) -> AppInit<T, B> {
         AppInit {
-            data: Rc::new(self.data),
-            data_factories: Rc::new(self.data_factories),
+            data: self.data.into_boxed_slice().into(),
+            data_factories: self.data_factories.into_boxed_slice().into(),
             endpoint: self.endpoint,
             services: Rc::new(RefCell::new(self.services)),
             external: RefCell::new(self.external),
diff --git a/src/app_service.rs b/src/app_service.rs
index 98d8c8a8..e5f8dd9c 100644
--- a/src/app_service.rs
+++ b/src/app_service.rs
@@ -39,8 +39,8 @@ where
 {
     pub(crate) endpoint: T,
     pub(crate) extensions: RefCell<Option<Extensions>>,
-    pub(crate) data: Rc<Vec<Box<dyn DataFactory>>>,
-    pub(crate) data_factories: Rc<Vec<FnDataFactory>>,
+    pub(crate) data: Rc<[Box<dyn DataFactory>]>,
+    pub(crate) data_factories: Rc<[FnDataFactory]>,
     pub(crate) services: Rc<RefCell<Vec<Box<dyn AppServiceFactory>>>>,
     pub(crate) default: Option<Rc<HttpNewService>>,
     pub(crate) factory_ref: Rc<RefCell<Option<AppRoutingFactory>>>,
@@ -88,15 +88,15 @@ where
         // complete pipeline creation
         *self.factory_ref.borrow_mut() = Some(AppRoutingFactory {
             default,
-            services: Rc::new(
-                services
-                    .into_iter()
-                    .map(|(mut rdef, srv, guards, nested)| {
-                        rmap.add(&mut rdef, nested);
-                        (rdef, srv, RefCell::new(guards))
-                    })
-                    .collect(),
-            ),
+            services: services
+                .into_iter()
+                .map(|(mut rdef, srv, guards, nested)| {
+                    rmap.add(&mut rdef, nested);
+                    (rdef, srv, RefCell::new(guards))
+                })
+                .collect::<Vec<_>>()
+                .into_boxed_slice()
+                .into(),
         });
 
         // external resources
@@ -147,7 +147,7 @@ where
 
     rmap: Rc<ResourceMap>,
     config: AppConfig,
-    data: Rc<Vec<Box<dyn DataFactory>>>,
+    data: Rc<[Box<dyn DataFactory>]>,
     extensions: Option<Extensions>,
 
     _t: PhantomData<B>,
@@ -273,7 +273,7 @@ where
 }
 
 pub struct AppRoutingFactory {
-    services: Rc<Vec<(ResourceDef, HttpNewService, RefCell<Option<Guards>>)>>,
+    services: Rc<[(ResourceDef, HttpNewService, RefCell<Option<Guards>>)]>,
     default: Rc<HttpNewService>,
 }
 
diff --git a/src/config.rs b/src/config.rs
index 0f49288e..f7bebb4c 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -31,7 +31,7 @@ pub struct AppService {
         Option<Guards>,
         Option<Rc<ResourceMap>>,
     )>,
-    service_data: Rc<Vec<Box<dyn DataFactory>>>,
+    service_data: Rc<[Box<dyn DataFactory>]>,
 }
 
 impl AppService {
@@ -39,7 +39,7 @@ impl AppService {
     pub(crate) fn new(
         config: AppConfig,
         default: Rc<HttpNewService>,
-        service_data: Rc<Vec<Box<dyn DataFactory>>>,
+        service_data: Rc<[Box<dyn DataFactory>]>,
     ) -> Self {
         AppService {
             config,
diff --git a/src/lib.rs b/src/lib.rs
index edc8456b..327cba95 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -67,7 +67,6 @@
 
 #![deny(rust_2018_idioms)]
 #![allow(clippy::needless_doctest_main, clippy::type_complexity)]
-#![allow(clippy::rc_buffer)] // FXIME: We should take a closer look for the warnings at some point.
 #![doc(html_logo_url = "https://actix.rs/img/logo.png")]
 #![doc(html_favicon_url = "https://actix.rs/favicon.ico")]
 
diff --git a/src/route.rs b/src/route.rs
index 129a6733..e9e9d1f5 100644
--- a/src/route.rs
+++ b/src/route.rs
@@ -1,3 +1,5 @@
+#![allow(clippy::rc_buffer)] // inner value is mutated before being shared (`Rc::get_mut`)
+
 use std::future::Future;
 use std::pin::Pin;
 use std::rc::Rc;
diff --git a/src/scope.rs b/src/scope.rs
index 2520fd7a..1c5d8700 100644
--- a/src/scope.rs
+++ b/src/scope.rs
@@ -442,16 +442,17 @@ where
         *self.factory_ref.borrow_mut() = Some(ScopeFactory {
             data: self.data.take().map(Rc::new),
             default: self.default.clone(),
-            services: Rc::new(
-                cfg.into_services()
-                    .1
-                    .into_iter()
-                    .map(|(mut rdef, srv, guards, nested)| {
-                        rmap.add(&mut rdef, nested);
-                        (rdef, srv, RefCell::new(guards))
-                    })
-                    .collect(),
-            ),
+            services: cfg
+                .into_services()
+                .1
+                .into_iter()
+                .map(|(mut rdef, srv, guards, nested)| {
+                    rmap.add(&mut rdef, nested);
+                    (rdef, srv, RefCell::new(guards))
+                })
+                .collect::<Vec<_>>()
+                .into_boxed_slice()
+                .into(),
         });
 
         // get guards
@@ -473,7 +474,7 @@ where
 
 pub struct ScopeFactory {
     data: Option<Rc<Extensions>>,
-    services: Rc<Vec<(ResourceDef, HttpNewService, RefCell<Option<Guards>>)>>,
+    services: Rc<[(ResourceDef, HttpNewService, RefCell<Option<Guards>>)]>,
     default: Rc<RefCell<Option<Rc<HttpNewService>>>>,
 }