diff --git a/Cargo.lock b/Cargo.lock
index c62cc6cb..a005b4b3 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -36,7 +36,7 @@ dependencies = [
  "ident_case",
  "proc-macro2 1.0.18",
  "quote 1.0.7",
- "syn 1.0.33",
+ "syn 1.0.34",
  "synstructure",
 ]
 
@@ -51,9 +51,9 @@ dependencies = [
 
 [[package]]
 name = "adler"
-version = "0.2.2"
+version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ccc9a9dd069569f212bc4330af9f17c4afb5e8ce185e83dbb14f1349dda18b10"
+checksum = "ee2a4ec343196209d6594e19543ae87a39f96d5534d7174822a3ad825dd6ed7e"
 
 [[package]]
 name = "aho-corasick"
@@ -426,7 +426,7 @@ dependencies = [
  "proc-macro2 1.0.18",
  "quote 1.0.7",
  "strsim 0.9.3",
- "syn 1.0.33",
+ "syn 1.0.34",
 ]
 
 [[package]]
@@ -437,7 +437,7 @@ checksum = "d9b5a2f4ac4969822c62224815d069952656cadc7084fdca9751e6d959189b72"
 dependencies = [
  "darling_core",
  "quote 1.0.7",
- "syn 1.0.33",
+ "syn 1.0.34",
 ]
 
 [[package]]
@@ -455,7 +455,7 @@ version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d3dd60d1080a57a05ab032377049e0591415d2b31afd7028356dbf3cc6dcb066"
 dependencies = [
- "generic-array 0.14.2",
+ "generic-array 0.14.3",
 ]
 
 [[package]]
@@ -466,7 +466,7 @@ checksum = "e6269d127174b18c665e683e23c2c55d3735fadbec4181c7c70b0450b764bfa5"
 dependencies = [
  "proc-macro2 1.0.18",
  "quote 1.0.7",
- "syn 1.0.33",
+ "syn 1.0.34",
 ]
 
 [[package]]
@@ -489,12 +489,6 @@ dependencies = [
  "thiserror",
 ]
 
-[[package]]
-name = "either"
-version = "1.5.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bb1f6b1ce1c140482ea30ddd3335fc0024ac7ee112895426e0a629a6c20adfe3"
-
 [[package]]
 name = "equihash"
 version = "0.1.0"
@@ -616,7 +610,7 @@ dependencies = [
  "proc-macro-hack",
  "proc-macro2 1.0.18",
  "quote 1.0.7",
- "syn 1.0.33",
+ "syn 1.0.34",
 ]
 
 [[package]]
@@ -683,9 +677,9 @@ dependencies = [
 
 [[package]]
 name = "generic-array"
-version = "0.14.2"
+version = "0.14.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ac746a5f3bbfdadd6106868134545e684693d54d9d44f6e9588a7d54af0bf980"
+checksum = "60fb4bb6bba52f78a471264d9a3b7d026cc0af47b22cd2cffbc0b787ca003e63"
 dependencies = [
  "typenum",
  "version_check",
@@ -725,14 +719,14 @@ checksum = "90454ce4de40b7ca6a8968b5ef367bdab48413962588d0d2b1638d60090c35d7"
 dependencies = [
  "proc-macro2 1.0.18",
  "quote 1.0.7",
- "syn 1.0.33",
+ "syn 1.0.34",
 ]
 
 [[package]]
 name = "h2"
-version = "0.2.5"
+version = "0.2.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "79b7246d7e4b979c03fa093da39cfb3617a96bbeee6310af63991668d7e843ff"
+checksum = "993f9e0baeed60001cf565546b0d3dbe6a6ad23f2bd31644a133c641eccf6d53"
 dependencies = [
  "bytes",
  "fnv",
@@ -741,10 +735,10 @@ dependencies = [
  "futures-util",
  "http",
  "indexmap",
- "log",
  "slab",
  "tokio",
  "tokio-util 0.3.1",
+ "tracing",
 ]
 
 [[package]]
@@ -1283,7 +1277,7 @@ checksum = "6a0ffd45cf79d88737d7cc85bfd5d2894bee1139b356e616fe85dc389c61aaf7"
 dependencies = [
  "proc-macro2 1.0.18",
  "quote 1.0.7",
- "syn 1.0.33",
+ "syn 1.0.34",
 ]
 
 [[package]]
@@ -1313,7 +1307,7 @@ dependencies = [
  "proc-macro-error-attr",
  "proc-macro2 1.0.18",
  "quote 1.0.7",
- "syn 1.0.33",
+ "syn 1.0.34",
  "version_check",
 ]
 
@@ -1325,7 +1319,7 @@ checksum = "3cc9795ca17eb581285ec44936da7fc2335a3f34f2ddd13118b6f4d515435c50"
 dependencies = [
  "proc-macro2 1.0.18",
  "quote 1.0.7",
- "syn 1.0.33",
+ "syn 1.0.34",
  "syn-mid",
  "version_check",
 ]
@@ -1529,9 +1523,9 @@ dependencies = [
 
 [[package]]
 name = "redox_syscall"
-version = "0.1.56"
+version = "0.1.57"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2439c63f3f6139d1b57529d16bc3b8bb855230c8efcc5d3a896c8bea7c3b1e84"
+checksum = "41cc0f7e4d5d4544e8861606a285bb08d3e70712ccc7d2b84d7c0ccfaf4b05ce"
 
 [[package]]
 name = "regex"
@@ -1701,7 +1695,7 @@ checksum = "2a0be94b04690fbaed37cddffc5c134bf537c8e3329d53e982fe04c374978f8e"
 dependencies = [
  "proc-macro2 1.0.18",
  "quote 1.0.7",
- "syn 1.0.33",
+ "syn 1.0.34",
 ]
 
 [[package]]
@@ -1847,7 +1841,7 @@ checksum = "5254766110c377a921c002ca0775d4e384ba69af951fc4329d9dd77af2c25763"
 dependencies = [
  "proc-macro2 1.0.18",
  "quote 1.0.7",
- "syn 1.0.33",
+ "syn 1.0.34",
 ]
 
 [[package]]
@@ -1883,7 +1877,7 @@ dependencies = [
  "proc-macro-error",
  "proc-macro2 1.0.18",
  "quote 1.0.7",
- "syn 1.0.33",
+ "syn 1.0.34",
 ]
 
 [[package]]
@@ -1905,9 +1899,9 @@ dependencies = [
 
 [[package]]
 name = "syn"
-version = "1.0.33"
+version = "1.0.34"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e8d5d96e8cbb005d6959f119f773bfaebb5684296108fb32600c00cde305b2cd"
+checksum = "936cae2873c940d92e697597c5eee105fb570cd5689c695806f672883653349b"
 dependencies = [
  "proc-macro2 1.0.18",
  "quote 1.0.7",
@@ -1922,7 +1916,7 @@ checksum = "7be3539f6c128a931cf19dcee741c1af532c7fd387baa739c03dd2e96479338a"
 dependencies = [
  "proc-macro2 1.0.18",
  "quote 1.0.7",
- "syn 1.0.33",
+ "syn 1.0.34",
 ]
 
 [[package]]
@@ -1933,7 +1927,7 @@ checksum = "b834f2d66f734cb897113e34aaff2f1ab4719ca946f9a7358dba8f8064148701"
 dependencies = [
  "proc-macro2 1.0.18",
  "quote 1.0.7",
- "syn 1.0.33",
+ "syn 1.0.34",
  "unicode-xid 0.2.1",
 ]
 
@@ -1996,7 +1990,7 @@ checksum = "bd80fc12f73063ac132ac92aceea36734f04a1d93c1240c6944e23a3b8841793"
 dependencies = [
  "proc-macro2 1.0.18",
  "quote 1.0.7",
- "syn 1.0.33",
+ "syn 1.0.34",
 ]
 
 [[package]]
@@ -2050,7 +2044,7 @@ checksum = "f0c3acc6aa564495a0f2e1d59fab677cd7f81a19994cfc7f3ad0e64301560389"
 dependencies = [
  "proc-macro2 1.0.18",
  "quote 1.0.7",
- "syn 1.0.33",
+ "syn 1.0.34",
 ]
 
 [[package]]
@@ -2154,7 +2148,6 @@ dependencies = [
 name = "tower-fallback"
 version = "0.1.0"
 dependencies = [
- "either",
  "futures-core",
  "pin-project",
  "tokio",
@@ -2272,7 +2265,7 @@ checksum = "f0693bf8d6f2bf22c690fc61a9d21ac69efdbb894a17ed596b9af0f01e64b84b"
 dependencies = [
  "proc-macro2 1.0.18",
  "quote 1.0.7",
- "syn 1.0.33",
+ "syn 1.0.34",
 ]
 
 [[package]]
@@ -2347,9 +2340,9 @@ dependencies = [
 
 [[package]]
 name = "try-lock"
-version = "0.2.2"
+version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e604eb7b43c06650e854be16a2a03155743d3752dd1c943f6829e26b7a36e382"
+checksum = "59547bce71d9c38b83d9c0e92b6066c4253371f15005def0c30d9657f50c7642"
 
 [[package]]
 name = "typenum"
@@ -2678,6 +2671,6 @@ checksum = "de251eec69fc7c1bc3923403d18ececb929380e016afe103da75f396704f8ca2"
 dependencies = [
  "proc-macro2 1.0.18",
  "quote 1.0.7",
- "syn 1.0.33",
+ "syn 1.0.34",
  "synstructure",
 ]
diff --git a/tower-fallback/Cargo.toml b/tower-fallback/Cargo.toml
index 1ed992d2..5c8a68b7 100644
--- a/tower-fallback/Cargo.toml
+++ b/tower-fallback/Cargo.toml
@@ -6,7 +6,6 @@ license = "MIT"
 edition = "2018"
 
 [dependencies]
-either = "1.5"
 tower = "0.3"
 futures-core = "0.3.5"
 pin-project = "0.4.20"
diff --git a/tower-fallback/src/future.rs b/tower-fallback/src/future.rs
index 312ac66e..59019acf 100644
--- a/tower-fallback/src/future.rs
+++ b/tower-fallback/src/future.rs
@@ -7,11 +7,12 @@ use std::{
     task::{Context, Poll},
 };
 
-use either::Either;
 use futures_core::ready;
 use pin_project::pin_project;
 use tower::Service;
 
+use crate::BoxedError;
+
 /// Future that completes either with the first service's successful response, or
 /// with the second service's response.
 #[pin_project]
@@ -19,6 +20,7 @@ pub struct ResponseFuture<S1, S2, Request>
 where
     S1: Service<Request>,
     S2: Service<Request, Response = <S1 as Service<Request>>::Response>,
+    S2::Error: Into<BoxedError>,
 {
     #[pin]
     state: ResponseState<S1, S2, Request>,
@@ -29,6 +31,7 @@ enum ResponseState<S1, S2, Request>
 where
     S1: Service<Request>,
     S2: Service<Request>,
+    S2::Error: Into<BoxedError>,
 {
     PollResponse1 {
         #[pin]
@@ -52,6 +55,7 @@ impl<S1, S2, Request> ResponseFuture<S1, S2, Request>
 where
     S1: Service<Request>,
     S2: Service<Request, Response = <S1 as Service<Request>>::Response>,
+    S2::Error: Into<BoxedError>,
 {
     pub(crate) fn new(fut: S1::Future, req: Request, svc2: S2) -> Self {
         ResponseFuture {
@@ -64,11 +68,9 @@ impl<S1, S2, Request> Future for ResponseFuture<S1, S2, Request>
 where
     S1: Service<Request>,
     S2: Service<Request, Response = <S1 as Service<Request>>::Response>,
+    S2::Error: Into<BoxedError>,
 {
-    type Output = Result<
-        <S1 as Service<Request>>::Response,
-        Either<<S1 as Service<Request>>::Error, <S2 as Service<Request>>::Error>,
-    >;
+    type Output = Result<<S1 as Service<Request>>::Response, BoxedError>;
 
     fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
         let mut this = self.project();
@@ -88,7 +90,7 @@ where
                     }
                 },
                 ResponseStateProj::PollReady2 { svc2, .. } => match ready!(svc2.poll_ready(cx)) {
-                    Err(e) => return Poll::Ready(Err(Either::Right(e))),
+                    Err(e) => return Poll::Ready(Err(e.into())),
                     Ok(()) => {
                         if let __ResponseStateProjectionOwned::PollReady2 { mut svc2, req } =
                             this.state.as_mut().project_replace(ResponseState::Tmp)
@@ -102,7 +104,7 @@ where
                     }
                 },
                 ResponseStateProj::PollResponse2 { fut } => {
-                    return fut.poll(cx).map_err(Either::Right)
+                    return fut.poll(cx).map_err(Into::into)
                 }
                 ResponseStateProj::Tmp => unreachable!(),
             }
@@ -118,6 +120,7 @@ where
     S1::Future: Debug,
     S2: Debug,
     S2::Future: Debug,
+    S2::Error: Into<BoxedError>,
 {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         f.debug_struct("ResponseFuture")
@@ -134,6 +137,7 @@ where
     S1::Future: Debug,
     S2: Debug,
     S2::Future: Debug,
+    S2::Error: Into<BoxedError>,
 {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
diff --git a/tower-fallback/src/lib.rs b/tower-fallback/src/lib.rs
index 705df28e..533f4c8a 100644
--- a/tower-fallback/src/lib.rs
+++ b/tower-fallback/src/lib.rs
@@ -6,4 +6,5 @@ pub mod future;
 mod service;
 
 pub use self::service::Fallback;
-pub use either::Either;
+
+pub type BoxedError = Box<dyn std::error::Error + Send + Sync + 'static>;
diff --git a/tower-fallback/src/service.rs b/tower-fallback/src/service.rs
index cd171ff4..99c5c53a 100644
--- a/tower-fallback/src/service.rs
+++ b/tower-fallback/src/service.rs
@@ -1,9 +1,10 @@
-use super::future::ResponseFuture;
-
-use either::Either;
 use std::task::{Context, Poll};
+
 use tower::Service;
 
+use super::future::ResponseFuture;
+use crate::BoxedError;
+
 /// Provides fallback processing on a second service if the first service returned an error.
 #[derive(Debug)]
 pub struct Fallback<S1, S2>
@@ -36,15 +37,17 @@ impl<S1, S2, Request> Service<Request> for Fallback<S1, S2>
 where
     S1: Service<Request>,
     S2: Service<Request, Response = <S1 as Service<Request>>::Response>,
+    S1::Error: Into<BoxedError>,
+    S2::Error: Into<BoxedError>,
     S2: Clone,
     Request: Clone,
 {
     type Response = <S1 as Service<Request>>::Response;
-    type Error = Either<<S1 as Service<Request>>::Error, <S2 as Service<Request>>::Error>;
+    type Error = BoxedError;
     type Future = ResponseFuture<S1, S2, Request>;
 
     fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
-        self.svc1.poll_ready(cx).map_err(Either::Left)
+        self.svc1.poll_ready(cx).map_err(Into::into)
     }
 
     fn call(&mut self, request: Request) -> Self::Future {
diff --git a/tower-fallback/tests/fallback.rs b/tower-fallback/tests/fallback.rs
index 3420fdcf..58abe078 100644
--- a/tower-fallback/tests/fallback.rs
+++ b/tower-fallback/tests/fallback.rs
@@ -1,5 +1,5 @@
 use tower::{service_fn, Service, ServiceExt};
-use tower_fallback::{Either, Fallback};
+use tower_fallback::Fallback;
 
 #[tokio::test]
 async fn fallback() {
@@ -24,10 +24,7 @@ async fn fallback() {
 
     let mut svc = Fallback::new(svc1, svc2);
 
-    assert_eq!(svc.ready_and().await.unwrap().call(1).await, Ok(1));
-    assert_eq!(svc.ready_and().await.unwrap().call(11).await, Ok(111));
-    assert_eq!(
-        svc.ready_and().await.unwrap().call(21).await,
-        Err(Either::Right("too big value on svc2"))
-    );
+    assert_eq!(svc.ready_and().await.unwrap().call(1).await.unwrap(), 1);
+    assert_eq!(svc.ready_and().await.unwrap().call(11).await.unwrap(), 111);
+    assert!(svc.ready_and().await.unwrap().call(21).await.is_err());
 }