diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index c60296707..9d1679d50 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -7,7 +7,7 @@ on:
   pull_request: {}
 
 env:
-  MSRV: 1.49.0
+  MSRV: 1.63.0
 
 jobs:
   check-stable:
diff --git a/README.md b/README.md
index 31a2357a9..a0716a42f 100644
--- a/README.md
+++ b/README.md
@@ -33,7 +33,7 @@ pattern. If your protocol is entirely stream based, Tower may not be a good fit.
 
 Tower will keep a rolling MSRV (minimum supported Rust version) policy of **at
 least** 6 months. When increasing the MSRV, the new Rust version must have been
-released at least six months ago. The current MSRV is 1.49.0.
+released at least six months ago. The current MSRV is 1.63.0.
 
 ## Getting Started
 
diff --git a/deny.toml b/deny.toml
index 83988ef34..111567196 100644
--- a/deny.toml
+++ b/deny.toml
@@ -2,7 +2,6 @@
 vulnerability = "deny"
 unmaintained = "warn"
 notice = "warn"
-ignore = ["RUSTSEC-2020-0159"]
 
 [licenses]
 unlicensed = "deny"
diff --git a/tower/Cargo.toml b/tower/Cargo.toml
index 96269dc80..3e199a844 100644
--- a/tower/Cargo.toml
+++ b/tower/Cargo.toml
@@ -20,7 +20,7 @@ clients and servers.
 categories = ["asynchronous", "network-programming"]
 keywords = ["io", "async", "non-blocking", "futures", "service"]
 edition = "2018"
-rust-version = "1.49.0"
+rust-version = "1.63.0"
 
 [features]
 
@@ -71,7 +71,7 @@ tower-service = { version = "0.3.1", path = "../tower-service" }
 futures-core = { version = "0.3", optional = true }
 futures-util = { version = "0.3", default-features = false, features = ["alloc"], optional = true }
 hdrhistogram = { version = "7.0", optional = true, default-features = false }
-indexmap = { version = "1.0.2", optional = true }
+indexmap = { version = "2.0.2", optional = true }
 slab = { version = "0.4", optional = true }
 tokio = { version = "1.6", optional = true, features = ["sync"] }
 tokio-stream = { version = "0.1.0", optional = true }
diff --git a/tower/README.md b/tower/README.md
index f5bc7d01e..b277f7433 100644
--- a/tower/README.md
+++ b/tower/README.md
@@ -174,7 +174,7 @@ Tower.
 
 Tower will keep a rolling MSRV (minimum supported Rust version) policy of **at
 least** 6 months. When increasing the MSRV, the new Rust version must have been
-released at least six months ago. The current MSRV is 1.49.0.
+released at least six months ago. The current MSRV is 1.63.0.
 
 ## License
 
diff --git a/tower/src/lib.rs b/tower/src/lib.rs
index 073fd016f..a509b89cb 100644
--- a/tower/src/lib.rs
+++ b/tower/src/lib.rs
@@ -144,7 +144,7 @@
 //!
 //! Tower will keep a rolling MSRV (minimum supported Rust version) policy of **at
 //! least** 6 months. When increasing the MSRV, the new Rust version must have been
-//! released at least six months ago. The current MSRV is 1.49.0.
+//! released at least six months ago. The current MSRV is 1.63.0.
 //!
 //! [`Service`]: crate::Service
 //! [`Layer`]: crate::Layer
@@ -202,15 +202,20 @@ pub mod layer;
 
 #[cfg(feature = "util")]
 #[doc(inline)]
+#[cfg_attr(docsrs, doc(cfg(feature = "util")))]
 pub use self::util::{service_fn, ServiceExt};
 
 #[doc(inline)]
 pub use crate::builder::ServiceBuilder;
+
 #[cfg(feature = "make")]
 #[doc(inline)]
+#[cfg_attr(docsrs, doc(cfg(feature = "make")))]
 pub use crate::make::MakeService;
+
 #[doc(inline)]
 pub use tower_layer::Layer;
+
 #[doc(inline)]
 pub use tower_service::Service;
 
diff --git a/tower/src/ready_cache/cache.rs b/tower/src/ready_cache/cache.rs
index 282f2bb83..304047881 100644
--- a/tower/src/ready_cache/cache.rs
+++ b/tower/src/ready_cache/cache.rs
@@ -193,7 +193,7 @@ where
     }
 
     /// Obtains a mutable reference to a service in the ready set by index.
-    pub fn get_ready_index_mut(&mut self, idx: usize) -> Option<(&mut K, &mut S)> {
+    pub fn get_ready_index_mut(&mut self, idx: usize) -> Option<(&K, &mut S)> {
         self.ready.get_index_mut(idx).map(|(k, v)| (k, &mut v.0))
     }
 
diff --git a/tower/src/reconnect/mod.rs b/tower/src/reconnect/mod.rs
index 80c6c2eb0..0062fe398 100644
--- a/tower/src/reconnect/mod.rs
+++ b/tower/src/reconnect/mod.rs
@@ -49,7 +49,7 @@ where
     M: Service<Target>,
 {
     /// Lazily connect and reconnect to a [`Service`].
-    pub const fn new<S, Request>(mk_service: M, target: Target) -> Self {
+    pub const fn new(mk_service: M, target: Target) -> Self {
         Reconnect {
             mk_service,
             state: State::Idle,
@@ -59,7 +59,7 @@ where
     }
 
     /// Reconnect to a already connected [`Service`].
-    pub fn with_connection(init_conn: M::Response, mk_service: M, target: Target) -> Self {
+    pub const fn with_connection(init_conn: M::Response, mk_service: M, target: Target) -> Self {
         Reconnect {
             mk_service,
             state: State::Connected(init_conn),