diff --git a/tower-async-http/_todo_examples/axum-key-value-store/main.rs b/tower-async-http/_todo_examples/axum-key-value-store/main.rs
index c9bd9a1..2b72b17 100644
--- a/tower-async-http/_todo_examples/axum-key-value-store/main.rs
+++ b/tower-async-http/_todo_examples/axum-key-value-store/main.rs
@@ -79,11 +79,11 @@ fn app() -> Router {
         .map_response_body(axum::body::boxed)
         // Compress responses
         .compression();
-        // Set a `Content-Type` if there isn't one already.
-        // .insert_response_header_if_not_present(
-        //     header::CONTENT_TYPE,
-        //     HeaderValue::from_static("application/octet-stream"),
-        // );
+    // Set a `Content-Type` if there isn't one already.
+    // .insert_response_header_if_not_present(
+    //     header::CONTENT_TYPE,
+    //     HeaderValue::from_static("application/octet-stream"),
+    // );
 
     let router_layer = middleware.into_classic();
 
diff --git a/tower-async-http/src/classify/grpc_errors_as_failures.rs b/tower-async-http/src/classify/grpc_errors_as_failures.rs
index ffc299c..3d2f8c3 100644
--- a/tower-async-http/src/classify/grpc_errors_as_failures.rs
+++ b/tower-async-http/src/classify/grpc_errors_as_failures.rs
@@ -207,7 +207,7 @@ impl ClassifyResponse for GrpcErrorsAsFailures {
 
     fn classify_error<E>(self, error: &E) -> Self::FailureClass
     where
-        E: fmt::Display + 'static,
+        E: fmt::Display,
     {
         GrpcFailureClass::Error(error.to_string())
     }
@@ -238,7 +238,7 @@ impl ClassifyEos for GrpcEosErrorsAsFailures {
 
     fn classify_error<E>(self, error: &E) -> Self::FailureClass
     where
-        E: fmt::Display + 'static,
+        E: fmt::Display,
     {
         GrpcFailureClass::Error(error.to_string())
     }
diff --git a/tower-async-http/src/classify/map_failure_class.rs b/tower-async-http/src/classify/map_failure_class.rs
index 680593b..254268d 100644
--- a/tower-async-http/src/classify/map_failure_class.rs
+++ b/tower-async-http/src/classify/map_failure_class.rs
@@ -54,7 +54,7 @@ where
 
     fn classify_error<E>(self, error: &E) -> Self::FailureClass
     where
-        E: std::fmt::Display + 'static,
+        E: std::fmt::Display,
     {
         (self.f)(self.inner.classify_error(error))
     }
@@ -73,7 +73,7 @@ where
 
     fn classify_error<E>(self, error: &E) -> Self::FailureClass
     where
-        E: std::fmt::Display + 'static,
+        E: std::fmt::Display,
     {
         (self.f)(self.inner.classify_error(error))
     }
diff --git a/tower-async-http/src/classify/mod.rs b/tower-async-http/src/classify/mod.rs
index 80808d2..eec5ebc 100644
--- a/tower-async-http/src/classify/mod.rs
+++ b/tower-async-http/src/classify/mod.rs
@@ -78,7 +78,7 @@ pub trait MakeClassifier {
 ///
 ///     fn classify_error<E>(self, error: &E) -> Self::FailureClass
 ///     where
-///         E: fmt::Display + 'static,
+///         E: fmt::Display,
 ///     {
 ///         error.to_string()
 ///     }
@@ -180,7 +180,7 @@ pub trait ClassifyResponse {
     /// errors. A retry policy might allow retrying some errors and not others.
     fn classify_error<E>(self, error: &E) -> Self::FailureClass
     where
-        E: fmt::Display + 'static;
+        E: fmt::Display;
 
     /// Transform the failure classification using a function.
     ///
@@ -251,7 +251,7 @@ pub trait ClassifyEos {
     /// errors. A retry policy might allow retrying some errors and not others.
     fn classify_error<E>(self, error: &E) -> Self::FailureClass
     where
-        E: fmt::Display + 'static;
+        E: fmt::Display;
 
     /// Transform the failure classification using a function.
     ///
@@ -293,7 +293,7 @@ impl<T> ClassifyEos for NeverClassifyEos<T> {
 
     fn classify_error<E>(self, _error: &E) -> Self::FailureClass
     where
-        E: fmt::Display + 'static,
+        E: fmt::Display,
     {
         // `NeverClassifyEos` contains an `Infallible` so it can never be constructed
         unreachable!()
@@ -346,7 +346,7 @@ impl ClassifyResponse for ServerErrorsAsFailures {
 
     fn classify_error<E>(self, error: &E) -> Self::FailureClass
     where
-        E: fmt::Display + 'static,
+        E: fmt::Display,
     {
         ServerErrorsFailureClass::Error(error.to_string())
     }
@@ -391,11 +391,11 @@ mod usable_for_retries {
     impl<ReqB, ResB, E, C> Policy<Request<ReqB>, Response<ResB>, E> for RetryBasedOnClassification<C>
     where
         C: ClassifyResponse + Clone,
-        E: fmt::Display + 'static,
+        E: fmt::Display,
         C::FailureClass: IsRetryable,
         ResB: http_body::Body,
         Request<ReqB>: Clone,
-        E: std::error::Error + 'static,
+        E: std::error::Error,
     {
         async fn retry(
             &self,
diff --git a/tower-async-http/src/classify/status_in_range_is_error.rs b/tower-async-http/src/classify/status_in_range_is_error.rs
index 4338101..069a11e 100644
--- a/tower-async-http/src/classify/status_in_range_is_error.rs
+++ b/tower-async-http/src/classify/status_in_range_is_error.rs
@@ -96,7 +96,7 @@ impl ClassifyResponse for StatusInRangeAsFailures {
 
     fn classify_error<E>(self, error: &E) -> Self::FailureClass
     where
-        E: std::fmt::Display + 'static,
+        E: std::fmt::Display,
     {
         StatusInRangeFailureClass::Error(error.to_string())
     }
diff --git a/tower-async-http/src/trace/body.rs b/tower-async-http/src/trace/body.rs
index 8a862e7..a7acdc8 100644
--- a/tower-async-http/src/trace/body.rs
+++ b/tower-async-http/src/trace/body.rs
@@ -31,7 +31,7 @@ impl<B, C, OnBodyChunkT, OnEosT, OnFailureT> Body
     for ResponseBody<B, C, OnBodyChunkT, OnEosT, OnFailureT>
 where
     B: Body,
-    B::Error: fmt::Display + 'static,
+    B::Error: fmt::Display,
     C: ClassifyEos,
     OnEosT: OnEos,
     OnBodyChunkT: OnBodyChunk<B::Data>,
diff --git a/tower-async-http/src/trace/mod.rs b/tower-async-http/src/trace/mod.rs
index dba03cf..d86748d 100644
--- a/tower-async-http/src/trace/mod.rs
+++ b/tower-async-http/src/trace/mod.rs
@@ -342,7 +342,7 @@
 //!
 //!     fn classify_error<E>(self, error: &E) -> Self::FailureClass
 //!     where
-//!         E: std::fmt::Display + 'static,
+//!         E: std::fmt::Display,
 //!     {
 //!         "something went wrong..."
 //!     }
diff --git a/tower-async-http/src/trace/on_eos.rs b/tower-async-http/src/trace/on_eos.rs
index ab90fc9..1ad0e8d 100644
--- a/tower-async-http/src/trace/on_eos.rs
+++ b/tower-async-http/src/trace/on_eos.rs
@@ -32,7 +32,7 @@ impl OnEos for () {
 
 impl<F> OnEos for F
 where
-    F: FnOnce(Option<&HeaderMap>, Duration, &Span),
+    F: Fn(Option<&HeaderMap>, Duration, &Span),
 {
     fn on_eos(self, trailers: Option<&HeaderMap>, stream_duration: Duration, span: &Span) {
         self(trailers, stream_duration, span)
diff --git a/tower-async-http/src/trace/on_response.rs b/tower-async-http/src/trace/on_response.rs
index c6ece84..f82748f 100644
--- a/tower-async-http/src/trace/on_response.rs
+++ b/tower-async-http/src/trace/on_response.rs
@@ -33,7 +33,7 @@ impl<B> OnResponse<B> for () {
 
 impl<B, F> OnResponse<B> for F
 where
-    F: FnOnce(&Response<B>, Duration, &Span),
+    F: Fn(&Response<B>, Duration, &Span),
 {
     fn on_response(self, response: &Response<B>, latency: Duration, span: &Span) {
         self(response, latency, span)
diff --git a/tower-async-http/src/trace/service.rs b/tower-async-http/src/trace/service.rs
index 5e25195..7ab3ee6 100644
--- a/tower-async-http/src/trace/service.rs
+++ b/tower-async-http/src/trace/service.rs
@@ -274,8 +274,8 @@ where
     S: Service<Request<ReqBody>, Response = Response<ResBody>>,
     ReqBody: Body,
     ResBody: Body,
-    ResBody::Error: fmt::Display + 'static,
-    S::Error: fmt::Display + 'static,
+    ResBody::Error: fmt::Display,
+    S::Error: fmt::Display,
     M: MakeClassifier,
     M::Classifier: Clone,
     MakeSpanT: MakeSpan<ReqBody>,
diff --git a/tower-async-service/src/lib.rs b/tower-async-service/src/lib.rs
index 64f5d2d..73715a3 100644
--- a/tower-async-service/src/lib.rs
+++ b/tower-async-service/src/lib.rs
@@ -137,7 +137,7 @@
 /// impl<T, Request> Service<Request> for Timeout<T>
 /// where
 ///     T: Service<Request>,
-///     T::Error: Into<Box<dyn Error + Send + Sync>> + 'static,
+///     T::Error: Into<Box<dyn Error + Send + Sync>>,
 ///     T::Response: 'static,
 /// {
 ///     // `Timeout` doesn't modify the response type, so we use `T`'s response type