diff --git a/dc/s2n-quic-dc/src/stream/recv/error.rs b/dc/s2n-quic-dc/src/stream/recv/error.rs
index e5cb85ac72..d38c2511a7 100644
--- a/dc/s2n-quic-dc/src/stream/recv/error.rs
+++ b/dc/s2n-quic-dc/src/stream/recv/error.rs
@@ -37,7 +37,7 @@ impl fmt::Display for Error {
     }
 }
 
-impl std::error::Error for Error {}
+impl core::error::Error for Error {}
 
 impl IntoEvent<Error> for Error {
     fn into_event(self) -> Error {
diff --git a/dc/s2n-quic-dc/src/stream/send/error.rs b/dc/s2n-quic-dc/src/stream/send/error.rs
index eeb34c3f81..9da543d541 100644
--- a/dc/s2n-quic-dc/src/stream/send/error.rs
+++ b/dc/s2n-quic-dc/src/stream/send/error.rs
@@ -34,7 +34,7 @@ impl fmt::Display for Error {
     }
 }
 
-impl std::error::Error for Error {}
+impl core::error::Error for Error {}
 
 impl IntoEvent<Error> for Error {
     fn into_event(self) -> Error {
diff --git a/quic/s2n-quic-core/events/connection.rs b/quic/s2n-quic-core/events/connection.rs
index c0a84e26f8..c5108afed8 100644
--- a/quic/s2n-quic-core/events/connection.rs
+++ b/quic/s2n-quic-core/events/connection.rs
@@ -345,6 +345,7 @@ struct TlsExporterReady<'a> {
 #[event("connectivity:tls_handshake_failed")]
 struct TlsHandshakeFailed<'a> {
     session: crate::event::TlsSession<'a>,
+    error: &'a (dyn core::error::Error + Send + Sync + 'static),
 }
 
 #[event("connectivity:path_challenge_updated")]
diff --git a/quic/s2n-quic-core/src/application/error.rs b/quic/s2n-quic-core/src/application/error.rs
index 3a46554e52..ebd2ef1cf0 100644
--- a/quic/s2n-quic-core/src/application/error.rs
+++ b/quic/s2n-quic-core/src/application/error.rs
@@ -18,8 +18,7 @@ use core::{fmt, ops};
 #[derive(Copy, Clone, Eq, PartialEq)]
 pub struct Error(VarInt);
 
-#[cfg(feature = "std")]
-impl std::error::Error for Error {}
+impl core::error::Error for Error {}
 
 impl fmt::Debug for Error {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
diff --git a/quic/s2n-quic-core/src/buffer/deque.rs b/quic/s2n-quic-core/src/buffer/deque.rs
index 10f23cccea..2e78f2c09f 100644
--- a/quic/s2n-quic-core/src/buffer/deque.rs
+++ b/quic/s2n-quic-core/src/buffer/deque.rs
@@ -225,8 +225,7 @@ impl fmt::Display for FillError {
     }
 }
 
-#[cfg(feature = "std")]
-impl std::error::Error for FillError {}
+impl core::error::Error for FillError {}
 
 #[cfg(feature = "std")]
 impl From<FillError> for std::io::Error {
diff --git a/quic/s2n-quic-core/src/connection/error.rs b/quic/s2n-quic-core/src/connection/error.rs
index c2746bcb7c..b99a44c045 100644
--- a/quic/s2n-quic-core/src/connection/error.rs
+++ b/quic/s2n-quic-core/src/connection/error.rs
@@ -101,8 +101,7 @@ pub enum Error {
     },
 }
 
-#[cfg(feature = "std")]
-impl std::error::Error for Error {}
+impl core::error::Error for Error {}
 
 impl fmt::Display for Error {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
diff --git a/quic/s2n-quic-core/src/crypto/tls.rs b/quic/s2n-quic-core/src/crypto/tls.rs
index 6a5b916fce..01c8424099 100644
--- a/quic/s2n-quic-core/src/crypto/tls.rs
+++ b/quic/s2n-quic-core/src/crypto/tls.rs
@@ -166,6 +166,7 @@ pub trait Context<Crypto: crate::crypto::CryptoSuite> {
     fn on_tls_handshake_failed(
         &mut self,
         session: &impl TlsSession,
+        error: &(dyn core::error::Error + Send + Sync + 'static),
     ) -> Result<(), crate::transport::Error>;
 
     /// Receives data from the initial packet space
diff --git a/quic/s2n-quic-core/src/crypto/tls/offload.rs b/quic/s2n-quic-core/src/crypto/tls/offload.rs
index 21106e0587..a0edac5a64 100644
--- a/quic/s2n-quic-core/src/crypto/tls/offload.rs
+++ b/quic/s2n-quic-core/src/crypto/tls/offload.rs
@@ -21,7 +21,11 @@ pub trait Executor {
 
 /// Allows access to the TlsSession on handshake failure and when the exporter secret is ready.
 pub trait ExporterHandler {
-    fn on_tls_handshake_failed(&self, session: &impl TlsSession) -> Option<Box<dyn Any + Send>>;
+    fn on_tls_handshake_failed(
+        &self,
+        session: &impl TlsSession,
+        e: &(dyn core::error::Error + Send + Sync + 'static),
+    ) -> Option<Box<dyn Any + Send>>;
     fn on_tls_exporter_ready(&self, session: &impl TlsSession) -> Option<Box<dyn Any + Send>>;
 }
 
@@ -30,6 +34,7 @@ impl ExporterHandler for () {
     fn on_tls_handshake_failed(
         &self,
         _session: &impl TlsSession,
+        _e: &(dyn core::error::Error + Send + Sync + 'static),
     ) -> Option<Box<dyn std::any::Any + Send>> {
         None
     }
@@ -559,8 +564,9 @@ impl<S: CryptoSuite, H: ExporterHandler> tls::Context<S> for RemoteContext<'_, R
     fn on_tls_handshake_failed(
         &mut self,
         session: &impl tls::TlsSession,
+        e: &(dyn core::error::Error + Send + Sync + 'static),
     ) -> Result<(), crate::transport::Error> {
-        if let Some(context) = self.exporter_handler.on_tls_handshake_failed(session) {
+        if let Some(context) = self.exporter_handler.on_tls_handshake_failed(session, e) {
             match self.send_to_quic.push(Request::TlsContext(context)) {
                 Ok(_) => (),
                 Err(_) => self.error = Some(SLICE_ERROR),
diff --git a/quic/s2n-quic-core/src/crypto/tls/slow_tls.rs b/quic/s2n-quic-core/src/crypto/tls/slow_tls.rs
index 7beebf1bce..dfc33bb4a2 100644
--- a/quic/s2n-quic-core/src/crypto/tls/slow_tls.rs
+++ b/quic/s2n-quic-core/src/crypto/tls/slow_tls.rs
@@ -167,8 +167,9 @@ where
     fn on_tls_handshake_failed(
         &mut self,
         session: &impl tls::TlsSession,
+        e: &(dyn core::error::Error + Send + Sync + 'static),
     ) -> Result<(), transport::Error> {
-        self.0.on_tls_exporter_ready(session)
+        self.0.on_tls_handshake_failed(session, e)
     }
 
     fn receive_initial(&mut self, max_len: Option<usize>) -> Option<tls::Bytes> {
diff --git a/quic/s2n-quic-core/src/crypto/tls/testing.rs b/quic/s2n-quic-core/src/crypto/tls/testing.rs
index 4df2634215..d24a6713bc 100644
--- a/quic/s2n-quic-core/src/crypto/tls/testing.rs
+++ b/quic/s2n-quic-core/src/crypto/tls/testing.rs
@@ -779,6 +779,7 @@ where
     fn on_tls_handshake_failed(
         &mut self,
         _: &impl super::TlsSession,
+        _: &(dyn std::error::Error + Send + Sync),
     ) -> Result<(), crate::transport::Error> {
         Ok(())
     }
diff --git a/quic/s2n-quic-core/src/datagram/default.rs b/quic/s2n-quic-core/src/datagram/default.rs
index 8f2a95d67b..91ebd3799d 100644
--- a/quic/s2n-quic-core/src/datagram/default.rs
+++ b/quic/s2n-quic-core/src/datagram/default.rs
@@ -49,8 +49,7 @@ pub enum BuilderError {
     ZeroCapacity,
 }
 
-#[cfg(feature = "std")]
-impl std::error::Error for BuilderError {}
+impl core::error::Error for BuilderError {}
 
 impl fmt::Display for BuilderError {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
diff --git a/quic/s2n-quic-core/src/event.rs b/quic/s2n-quic-core/src/event.rs
index 5151a7ccf6..85ca93d504 100644
--- a/quic/s2n-quic-core/src/event.rs
+++ b/quic/s2n-quic-core/src/event.rs
@@ -66,7 +66,14 @@ ident_into_event!(
     connection::Error,
     endpoint::Location,
 );
-borrowed_into_event!([u8; 4], [u8; 16], [u8], [u32], [&'a [u8]]);
+borrowed_into_event!(
+    [u8; 4],
+    [u8; 16],
+    [u8],
+    [u32],
+    [&'a [u8]],
+    (dyn core::error::Error + Send + Sync + 'static)
+);
 
 impl<T: IntoEvent<U>, U> IntoEvent<Option<U>> for Option<T> {
     #[inline]
diff --git a/quic/s2n-quic-core/src/event/generated.rs b/quic/s2n-quic-core/src/event/generated.rs
index ead9b37843..d1be09194c 100644
--- a/quic/s2n-quic-core/src/event/generated.rs
+++ b/quic/s2n-quic-core/src/event/generated.rs
@@ -2468,12 +2468,14 @@ pub mod api {
     #[non_exhaustive]
     pub struct TlsHandshakeFailed<'a> {
         pub session: crate::event::TlsSession<'a>,
+        pub error: &'a (dyn core::error::Error + Send + Sync + 'static),
     }
     #[cfg(any(test, feature = "testing"))]
     impl<'a> crate::event::snapshot::Fmt for TlsHandshakeFailed<'a> {
         fn fmt(&self, fmt: &mut core::fmt::Formatter) -> core::fmt::Result {
             let mut fmt = fmt.debug_struct("TlsHandshakeFailed");
             fmt.field("session", &self.session);
+            fmt.field("error", &self.error);
             fmt.finish()
         }
     }
@@ -4132,8 +4134,8 @@ pub mod tracing {
             event: &api::TlsHandshakeFailed,
         ) {
             let id = context.id();
-            let api::TlsHandshakeFailed { session } = event;
-            tracing :: event ! (target : "tls_handshake_failed" , parent : id , tracing :: Level :: DEBUG , { session = tracing :: field :: debug (session) });
+            let api::TlsHandshakeFailed { session, error } = event;
+            tracing :: event ! (target : "tls_handshake_failed" , parent : id , tracing :: Level :: DEBUG , { session = tracing :: field :: debug (session) , error = tracing :: field :: debug (error) });
         }
         #[inline]
         fn on_path_challenge_updated(
@@ -6300,13 +6302,15 @@ pub mod builder {
     #[derive(Clone, Debug)]
     pub struct TlsHandshakeFailed<'a> {
         pub session: crate::event::TlsSession<'a>,
+        pub error: &'a (dyn core::error::Error + Send + Sync + 'static),
     }
     impl<'a> IntoEvent<api::TlsHandshakeFailed<'a>> for TlsHandshakeFailed<'a> {
         #[inline]
         fn into_event(self) -> api::TlsHandshakeFailed<'a> {
-            let TlsHandshakeFailed { session } = self;
+            let TlsHandshakeFailed { session, error } = self;
             api::TlsHandshakeFailed {
                 session: session.into_event(),
+                error: error.into_event(),
             }
         }
     }
diff --git a/quic/s2n-quic-core/src/path/mtu.rs b/quic/s2n-quic-core/src/path/mtu.rs
index ee17b3a447..52c084cdc1 100644
--- a/quic/s2n-quic-core/src/path/mtu.rs
+++ b/quic/s2n-quic-core/src/path/mtu.rs
@@ -241,8 +241,7 @@ impl Display for MtuError {
     }
 }
 
-#[cfg(feature = "std")]
-impl std::error::Error for MtuError {}
+impl core::error::Error for MtuError {}
 
 /// Information about the path that may be used when generating MTU configuration.
 #[non_exhaustive]
diff --git a/quic/s2n-quic-core/src/query.rs b/quic/s2n-quic-core/src/query.rs
index 562caf4748..3e8a8f5066 100644
--- a/quic/s2n-quic-core/src/query.rs
+++ b/quic/s2n-quic-core/src/query.rs
@@ -132,5 +132,4 @@ impl core::fmt::Display for Error {
     }
 }
 
-#[cfg(feature = "std")]
-impl std::error::Error for Error {}
+impl core::error::Error for Error {}
diff --git a/quic/s2n-quic-core/src/stream/error.rs b/quic/s2n-quic-core/src/stream/error.rs
index 36fb4a9c09..ab83c5a3f0 100644
--- a/quic/s2n-quic-core/src/stream/error.rs
+++ b/quic/s2n-quic-core/src/stream/error.rs
@@ -68,8 +68,7 @@ pub enum StreamError {
     },
 }
 
-#[cfg(feature = "std")]
-impl std::error::Error for StreamError {}
+impl core::error::Error for StreamError {}
 
 impl fmt::Display for StreamError {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
diff --git a/quic/s2n-quic-core/src/transport/error.rs b/quic/s2n-quic-core/src/transport/error.rs
index 815d49f591..2b41e9d23c 100644
--- a/quic/s2n-quic-core/src/transport/error.rs
+++ b/quic/s2n-quic-core/src/transport/error.rs
@@ -29,8 +29,7 @@ pub struct Error {
     pub reason: &'static str,
 }
 
-#[cfg(feature = "std")]
-impl std::error::Error for Error {}
+impl core::error::Error for Error {}
 
 impl Error {
     /// Creates a new `Error`
diff --git a/quic/s2n-quic-core/src/transport/parameters/mod.rs b/quic/s2n-quic-core/src/transport/parameters/mod.rs
index c3ae4764af..49d97dcc24 100644
--- a/quic/s2n-quic-core/src/transport/parameters/mod.rs
+++ b/quic/s2n-quic-core/src/transport/parameters/mod.rs
@@ -259,8 +259,7 @@ impl From<core::convert::Infallible> for ValidationError {
     }
 }
 
-#[cfg(feature = "std")]
-impl std::error::Error for ValidationError {}
+impl core::error::Error for ValidationError {}
 
 /// Creates a transport parameter struct with the inner codec type
 macro_rules! transport_parameter {
diff --git a/quic/s2n-quic-core/src/varint/mod.rs b/quic/s2n-quic-core/src/varint/mod.rs
index d99b611f3d..6279191d91 100644
--- a/quic/s2n-quic-core/src/varint/mod.rs
+++ b/quic/s2n-quic-core/src/varint/mod.rs
@@ -34,8 +34,7 @@ impl fmt::Display for VarIntError {
     }
 }
 
-#[cfg(feature = "std")]
-impl std::error::Error for VarIntError {}
+impl core::error::Error for VarIntError {}
 
 // === API ===
 
diff --git a/quic/s2n-quic-rustls/src/session.rs b/quic/s2n-quic-rustls/src/session.rs
index 32fd4558b6..9540f00528 100644
--- a/quic/s2n-quic-rustls/src/session.rs
+++ b/quic/s2n-quic-rustls/src/session.rs
@@ -381,8 +381,8 @@ impl tls::Session for Session {
         context: &mut C,
     ) -> Poll<Result<(), transport::Error>> {
         let result = self.poll_impl(context);
-        if let Poll::Ready(Err(_)) = &result {
-            context.on_tls_handshake_failed(self)?;
+        if let Poll::Ready(Err(e)) = &result {
+            context.on_tls_handshake_failed(self, e)?;
         }
         // attempt to emit server_name and application_protocol events prior to possibly
         // returning with an error
diff --git a/quic/s2n-quic-tests/src/tests/offload.rs b/quic/s2n-quic-tests/src/tests/offload.rs
index a2a7a699c3..6001f78442 100644
--- a/quic/s2n-quic-tests/src/tests/offload.rs
+++ b/quic/s2n-quic-tests/src/tests/offload.rs
@@ -18,6 +18,7 @@ impl ExporterHandler for Exporter {
     fn on_tls_handshake_failed(
         &self,
         _session: &impl s2n_quic_core::crypto::tls::TlsSession,
+        _e: &(dyn core::error::Error + Send + Sync + 'static),
     ) -> Option<Box<dyn std::any::Any + Send>> {
         None
     }
diff --git a/quic/s2n-quic-tls/src/session.rs b/quic/s2n-quic-tls/src/session.rs
index 7ae40c6651..44ba29d7af 100644
--- a/quic/s2n-quic-tls/src/session.rs
+++ b/quic/s2n-quic-tls/src/session.rs
@@ -162,7 +162,7 @@ impl tls::Session for Session {
                 Poll::Ready(Ok(()))
             }
             Poll::Ready(Err(e)) => {
-                context.on_tls_handshake_failed(self)?;
+                context.on_tls_handshake_failed(self, &e)?;
 
                 Poll::Ready(Err(e
                     .alert()
diff --git a/quic/s2n-quic-transport/src/space/session_context.rs b/quic/s2n-quic-transport/src/space/session_context.rs
index 747bf9724d..cfd84aeff7 100644
--- a/quic/s2n-quic-transport/src/space/session_context.rs
+++ b/quic/s2n-quic-transport/src/space/session_context.rs
@@ -570,10 +570,12 @@ impl<Config: endpoint::Config, Pub: event::ConnectionPublisher>
     fn on_tls_handshake_failed(
         &mut self,
         session: &impl tls::TlsSession,
+        e: &(dyn std::error::Error + Send + Sync + 'static),
     ) -> Result<(), transport::Error> {
         self.publisher
             .on_tls_handshake_failed(event::builder::TlsHandshakeFailed {
                 session: s2n_quic_core::event::TlsSession::new(session),
+                error: e,
             });
         Ok(())
     }
diff --git a/quic/s2n-quic/src/provider.rs b/quic/s2n-quic/src/provider.rs
index 91a34c4e6e..94edd856f8 100644
--- a/quic/s2n-quic/src/provider.rs
+++ b/quic/s2n-quic/src/provider.rs
@@ -77,7 +77,7 @@ cfg_if!(
 /// An error indicating a failure to start an endpoint
 pub struct StartError(Box<dyn 'static + fmt::Display + Send + Sync>);
 
-impl std::error::Error for StartError {}
+impl core::error::Error for StartError {}
 
 impl StartError {
     pub(crate) fn new<T: 'static + fmt::Display + Send + Sync>(error: T) -> Self {