diff --git a/hyper-balance/src/lib.rs b/hyper-balance/src/lib.rs
index ea8e61cb28..be44363d7e 100644
--- a/hyper-balance/src/lib.rs
+++ b/hyper-balance/src/lib.rs
@@ -34,7 +34,7 @@ pub struct PendingUntilEosBody<T, B> {
     body: B,
 }
 
-// ==== PendingUntilFirstData ====
+// === PendingUntilFirstData ===
 
 impl<T, B> TrackCompletion<T, http::Response<B>> for PendingUntilFirstData
 where
@@ -55,7 +55,7 @@ where
     }
 }
 
-// ==== PendingUntilEos ====
+// === PendingUntilEos ===
 
 impl<T, B> TrackCompletion<T, http::Response<B>> for PendingUntilEos
 where
@@ -76,7 +76,7 @@ where
     }
 }
 
-// ==== PendingUntilFirstDataBody ====
+// === PendingUntilFirstDataBody ===
 
 impl<T, B> Default for PendingUntilFirstDataBody<T, B>
 where
@@ -134,7 +134,7 @@ where
     }
 }
 
-// ==== PendingUntilEosBody ====
+// === PendingUntilEosBody ===
 
 impl<T, B> Default for PendingUntilEosBody<T, B>
 where
diff --git a/linkerd/app/integration/src/test_env.rs b/linkerd/app/integration/src/test_env.rs
index 2cd8e05ab7..da7886cd96 100644
--- a/linkerd/app/integration/src/test_env.rs
+++ b/linkerd/app/integration/src/test_env.rs
@@ -6,7 +6,7 @@ pub struct TestEnv {
     values: HashMap<&'static str, String>,
 }
 
-// ===== impl TestEnv =====
+// === impl TestEnv ===
 
 impl TestEnv {
     pub fn put(&mut self, key: &'static str, value: String) {
diff --git a/linkerd/app/src/env.rs b/linkerd/app/src/env.rs
index 61e662d379..fe7b8b4d28 100644
--- a/linkerd/app/src/env.rs
+++ b/linkerd/app/src/env.rs
@@ -922,7 +922,7 @@ fn convert_attributes_string_to_map(attributes: String) -> HashMap<String, Strin
         .collect()
 }
 
-// ===== impl Env =====
+// === impl Env ===
 
 impl Strings for Env {
     fn get(&self, key: &str) -> Result<Option<String>, EnvError> {
@@ -945,7 +945,7 @@ impl Env {
     }
 }
 
-// ===== Parsing =====
+// === Parsing ===
 
 /// There is a dependency on identity being enabled for tap to work. The
 /// status of tap is determined by the ENV_TAP_SVC_NAME env variable being set
diff --git a/linkerd/meshtls/tests/util.rs b/linkerd/meshtls/tests/util.rs
index 49c8bee0bd..0152da2aa4 100644
--- a/linkerd/meshtls/tests/util.rs
+++ b/linkerd/meshtls/tests/util.rs
@@ -357,7 +357,7 @@ impl Param<Keepalive> for Server {
     }
 }
 
-/// === impl ServerParams ===
+// === impl ServerParams ===
 
 impl<T> ExtractParam<tls::server::Timeout, T> for ServerParams {
     fn extract_param(&self, _: &T) -> tls::server::Timeout {
diff --git a/linkerd/metrics/src/counter.rs b/linkerd/metrics/src/counter.rs
index b95e3e5e30..9513c3df13 100644
--- a/linkerd/metrics/src/counter.rs
+++ b/linkerd/metrics/src/counter.rs
@@ -20,7 +20,7 @@ use std::sync::atomic::{AtomicU64, Ordering};
 #[derive(Debug)]
 pub struct Counter<F = ()>(AtomicU64, std::marker::PhantomData<F>);
 
-// ===== impl Counter =====
+// === impl Counter ===
 
 impl<F> Default for Counter<F> {
     fn default() -> Self {
diff --git a/linkerd/metrics/src/histogram.rs b/linkerd/metrics/src/histogram.rs
index 853f2c9b95..360fd6dbea 100644
--- a/linkerd/metrics/src/histogram.rs
+++ b/linkerd/metrics/src/histogram.rs
@@ -48,7 +48,7 @@ pub struct Bounds(pub &'static [Bucket]);
 /// Helper that lazily formats an `{K}="{V}"`" label.
 struct Label<K: fmt::Display, V: fmt::Display>(K, V);
 
-// ===== impl Histogram =====
+// === impl Histogram ===
 
 impl<V: Into<u64>, F: Factor> Histogram<V, F> {
     pub fn new(bounds: &'static Bounds) -> Self {
@@ -220,7 +220,7 @@ impl<V: Into<u64>, F: Factor> FmtMetric for Histogram<V, F> {
     }
 }
 
-// ===== impl Label =====
+// === impl Label ===
 
 impl<K: fmt::Display, V: fmt::Display> FmtLabels for Label<K, V> {
     fn fmt_labels(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
@@ -228,7 +228,7 @@ impl<K: fmt::Display, V: fmt::Display> FmtLabels for Label<K, V> {
     }
 }
 
-// ===== impl Bucket =====
+// === impl Bucket ===
 
 impl fmt::Display for Bucket {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
diff --git a/linkerd/metrics/src/prom.rs b/linkerd/metrics/src/prom.rs
index 89031a4227..16bc4ada4f 100644
--- a/linkerd/metrics/src/prom.rs
+++ b/linkerd/metrics/src/prom.rs
@@ -71,7 +71,7 @@ pub struct Metric<'a, N: fmt::Display, M: FmtMetric> {
     pub _p: PhantomData<M>,
 }
 
-// ===== impl Metric =====
+// === impl Metric ===
 
 impl<'a, N: fmt::Display, M: FmtMetric> Metric<'a, N, M> {
     pub fn new(name: N, help: &'a str) -> Self {
@@ -146,7 +146,7 @@ impl<N: Clone + fmt::Display, M: FmtMetric> Clone for Metric<'_, N, M> {
 
 impl<N: Copy + fmt::Display, M: FmtMetric> Copy for Metric<'_, N, M> {}
 
-// ===== impl FmtLabels =====
+// === impl FmtLabels ===
 
 impl<'a, A: FmtLabels + 'a> FmtLabels for &'a A {
     fn fmt_labels(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
@@ -188,7 +188,7 @@ impl<A: FmtLabels, B: FmtLabels> FmtLabels for (Option<A>, B) {
     }
 }
 
-// ===== impl FmtMetrics =====
+// === impl FmtMetrics ===
 
 impl<'a, A: FmtMetrics + 'a> FmtMetrics for &'a A {
     #[inline]
diff --git a/linkerd/metrics/src/serve.rs b/linkerd/metrics/src/serve.rs
index ee205cbaa4..96edfb6a03 100644
--- a/linkerd/metrics/src/serve.rs
+++ b/linkerd/metrics/src/serve.rs
@@ -11,7 +11,7 @@ pub struct Serve<M> {
     metrics: M,
 }
 
-// ===== impl Serve =====
+// === impl Serve ===
 
 impl<M> Serve<M> {
     pub fn new(metrics: M) -> Self {
diff --git a/linkerd/proxy/http/src/glue.rs b/linkerd/proxy/http/src/glue.rs
index a7d36f5cd7..4473023c6a 100644
--- a/linkerd/proxy/http/src/glue.rs
+++ b/linkerd/proxy/http/src/glue.rs
@@ -53,7 +53,7 @@ pub struct HyperConnectFuture<F> {
     inner: F,
     absolute_form: bool,
 }
-// ===== impl UpgradeBody =====
+// === impl UpgradeBody ===
 
 impl HttpBody for UpgradeBody {
     type Data = Bytes;
@@ -132,7 +132,7 @@ impl PinnedDrop for UpgradeBody {
     }
 }
 
-// ===== impl HyperServerSvc =====
+// === impl HyperServerSvc ===
 
 impl<S> HyperServerSvc<S> {
     pub fn new(service: S) -> Self {
@@ -157,7 +157,7 @@ where
     }
 }
 
-// ===== impl HyperConnect =====
+// === impl HyperConnect ===
 
 impl<C, T> HyperConnect<C, T> {
     pub(super) fn new(connect: C, target: T, absolute_form: bool) -> Self {
diff --git a/linkerd/proxy/http/src/upgrade.rs b/linkerd/proxy/http/src/upgrade.rs
index 50f3ba51fb..0398b6e12c 100644
--- a/linkerd/proxy/http/src/upgrade.rs
+++ b/linkerd/proxy/http/src/upgrade.rs
@@ -62,7 +62,7 @@ pub struct Service<S> {
     upgrade_drain_signal: drain::Watch,
 }
 
-// ===== impl Http11Upgrade =====
+// === impl Http11Upgrade ===
 
 impl Http11Upgrade {
     /// Returns a pair of upgrade handles.
@@ -160,7 +160,7 @@ impl Drop for Inner {
     }
 }
 
-// ===== impl Service =====
+// === impl Service ===
 impl<S> Service<S> {
     pub fn new(service: S, upgrade_drain_signal: drain::Watch) -> Self {
         Self {
diff --git a/linkerd/proxy/tap/src/grpc/match_.rs b/linkerd/proxy/tap/src/grpc/match_.rs
index 4156a92d8d..598a981199 100644
--- a/linkerd/proxy/tap/src/grpc/match_.rs
+++ b/linkerd/proxy/tap/src/grpc/match_.rs
@@ -58,7 +58,7 @@ pub enum HttpMatch {
     Authority(observe_request::r#match::http::string_match::Match),
 }
 
-// ===== impl Match ======
+// === impl Match ===
 
 impl Match {
     fn from_seq(seq: observe_request::r#match::Seq) -> Result<Vec<Self>, InvalidMatch> {
@@ -130,7 +130,7 @@ impl TryFrom<observe_request::r#match::Match> for Match {
     }
 }
 
-// ===== impl LabelMatch ======
+// === impl LabelMatch ===
 
 impl LabelMatch {
     fn matches(&self, labels: &BTreeMap<String, String>) -> bool {
@@ -153,7 +153,7 @@ impl TryFrom<observe_request::r#match::Label> for LabelMatch {
     }
 }
 
-// ===== impl TcpMatch ======
+// === impl TcpMatch ===
 
 impl TcpMatch {
     fn matches(&self, addr: net::SocketAddr) -> bool {
@@ -196,7 +196,7 @@ impl TryFrom<observe_request::r#match::Tcp> for TcpMatch {
     }
 }
 
-// ===== impl NetMatch ======
+// === impl NetMatch ===
 
 impl NetMatch {
     fn matches(&self, addr: &net::IpAddr) -> bool {
@@ -242,7 +242,7 @@ impl TryFrom<observe_request::r#match::tcp::Netmask> for NetMatch {
     }
 }
 
-// ===== impl HttpMatch ======
+// === impl HttpMatch ===
 
 impl HttpMatch {
     fn matches<B, I: Inspect>(&self, req: &http::Request<B>, inspect: &I) -> bool {
diff --git a/linkerd/stack/src/lib.rs b/linkerd/stack/src/lib.rs
index 4b6abb8c4b..4e156f5440 100644
--- a/linkerd/stack/src/lib.rs
+++ b/linkerd/stack/src/lib.rs
@@ -93,7 +93,7 @@ pub trait InsertParam<P, T> {
 #[derive(Copy, Clone, Debug)]
 pub struct CloneParam<P>(P);
 
-/// === Param ===
+// === Param ===
 
 /// The identity `Param`.
 impl<T: ToOwned> Param<T::Owned> for T {
@@ -103,7 +103,7 @@ impl<T: ToOwned> Param<T::Owned> for T {
     }
 }
 
-/// === ExtractParam ===
+// === ExtractParam ===
 
 impl<F, P, T> ExtractParam<P, T> for F
 where
@@ -135,7 +135,7 @@ impl<P: ToOwned, T> ExtractParam<P::Owned, T> for CloneParam<P> {
     }
 }
 
-/// === InsertParam ===
+// === InsertParam ===
 
 impl<P, T> InsertParam<P, T> for () {
     type Target = (P, T);