diff --git a/actix-service/src/apply.rs b/actix-service/src/apply.rs
index 1eb1cc8e..e6624057 100644
--- a/actix-service/src/apply.rs
+++ b/actix-service/src/apply.rs
@@ -17,7 +17,7 @@ where
 impl<T, F, In, Out, Request> Apply<T, F, In, Out, Request>
 where
     T: Service<Request>,
-    F: Fn(In, &mut T) -> Out,
+    F: FnMut(In, &mut T) -> Out,
     Out: IntoFuture,
     Out::Error: From<T::Error>,
 {
@@ -48,7 +48,7 @@ where
 impl<T, F, In, Out, Request> Service<In> for Apply<T, F, In, Out, Request>
 where
     T: Service<Request>,
-    F: Fn(In, &mut T) -> Out,
+    F: FnMut(In, &mut T) -> Out,
     Out: IntoFuture,
     Out::Error: From<T::Error>,
 {
diff --git a/actix-service/src/lib.rs b/actix-service/src/lib.rs
index a96dbd5b..1e033273 100644
--- a/actix-service/src/lib.rs
+++ b/actix-service/src/lib.rs
@@ -66,7 +66,7 @@ pub trait ServiceExt<Request>: Service<Request> {
         Self: Sized,
         T: Service<Req, Error = Self::Error>,
         I: IntoService<T, Req>,
-        F: Fn(Self::Response, &mut T) -> Out,
+        F: FnMut(Self::Response, &mut T) -> Out,
         Out: IntoFuture<Error = Self::Error>,
     {
         self.and_then(Apply::new(service.into_service(), f))
@@ -191,7 +191,7 @@ pub trait NewService<Request> {
         Self: Sized,
         T: NewService<Req, InitError = Self::InitError, Error = Self::Error>,
         I: IntoNewService<T, Req>,
-        F: Fn(Self::Response, &mut T::Service) -> Out + Clone,
+        F: FnMut(Self::Response, &mut T::Service) -> Out + Clone,
         Out: IntoFuture<Error = Self::Error>,
     {
         self.and_then(ApplyNewService::new(service, f))