diff --git a/tonic/src/transport/channel/service/tls.rs b/tonic/src/transport/channel/service/tls.rs
index 656e9fb31..629a4fe26 100644
--- a/tonic/src/transport/channel/service/tls.rs
+++ b/tonic/src/transport/channel/service/tls.rs
@@ -1,5 +1,4 @@
 use std::fmt;
-use std::io::Cursor;
 use std::sync::Arc;
 
 use hyper_util::rt::TokioIo;
@@ -13,7 +12,9 @@ use tokio_rustls::{
 };
 
 use super::io::BoxedIo;
-use crate::transport::service::tls::{add_certs_from_pem, load_identity, TlsError, ALPN_H2};
+use crate::transport::service::tls::{
+    convert_certificate_to_pki_types, convert_identity_to_pki_types, TlsError, ALPN_H2,
+};
 use crate::transport::tls::{Certificate, Identity};
 
 #[derive(Clone)]
@@ -55,13 +56,13 @@ impl TlsConnector {
         }
 
         for cert in ca_certs {
-            add_certs_from_pem(&mut Cursor::new(cert), &mut roots)?;
+            roots.add_parsable_certificates(convert_certificate_to_pki_types(&cert)?);
         }
 
         let builder = builder.with_root_certificates(roots);
         let mut config = match identity {
             Some(identity) => {
-                let (client_cert, client_key) = load_identity(identity)?;
+                let (client_cert, client_key) = convert_identity_to_pki_types(&identity)?;
                 builder.with_client_auth_cert(client_cert, client_key)?
             }
             None => builder.with_no_client_auth(),
diff --git a/tonic/src/transport/server/service/tls.rs b/tonic/src/transport/server/service/tls.rs
index d69a6a46b..395d5132b 100644
--- a/tonic/src/transport/server/service/tls.rs
+++ b/tonic/src/transport/server/service/tls.rs
@@ -1,4 +1,4 @@
-use std::{fmt, io::Cursor, sync::Arc};
+use std::{fmt, sync::Arc};
 
 use tokio::io::{AsyncRead, AsyncWrite};
 use tokio_rustls::{
@@ -8,7 +8,7 @@ use tokio_rustls::{
 };
 
 use crate::transport::{
-    service::tls::{add_certs_from_pem, load_identity, ALPN_H2},
+    service::tls::{convert_certificate_to_pki_types, convert_identity_to_pki_types, ALPN_H2},
     Certificate, Identity,
 };
 
@@ -29,7 +29,7 @@ impl TlsAcceptor {
             None => builder.with_no_client_auth(),
             Some(cert) => {
                 let mut roots = RootCertStore::empty();
-                add_certs_from_pem(&mut Cursor::new(cert), &mut roots)?;
+                roots.add_parsable_certificates(convert_certificate_to_pki_types(&cert)?);
                 let verifier = if client_auth_optional {
                     WebPkiClientVerifier::builder(roots.into()).allow_unauthenticated()
                 } else {
@@ -40,7 +40,7 @@ impl TlsAcceptor {
             }
         };
 
-        let (cert, key) = load_identity(identity)?;
+        let (cert, key) = convert_identity_to_pki_types(&identity)?;
         let mut config = builder.with_single_cert(cert, key)?;
 
         config.alpn_protocols.push(ALPN_H2.into());
diff --git a/tonic/src/transport/service/tls.rs b/tonic/src/transport/service/tls.rs
index cdc2cf7ee..1b0c1c458 100644
--- a/tonic/src/transport/service/tls.rs
+++ b/tonic/src/transport/service/tls.rs
@@ -1,11 +1,8 @@
 use std::{fmt, io::Cursor};
 
-use tokio_rustls::rustls::{
-    pki_types::{CertificateDer, PrivateKeyDer},
-    RootCertStore,
-};
+use tokio_rustls::rustls::pki_types::{CertificateDer, PrivateKeyDer};
 
-use crate::transport::Identity;
+use crate::transport::{Certificate, Identity};
 
 /// h2 alpn in plain format for rustls.
 pub(crate) const ALPN_H2: &[u8] = b"h2";
@@ -38,29 +35,20 @@ impl fmt::Display for TlsError {
 
 impl std::error::Error for TlsError {}
 
-pub(crate) fn load_identity(
-    identity: Identity,
-) -> Result<(Vec<CertificateDer<'static>>, PrivateKeyDer<'static>), TlsError> {
-    let cert = rustls_pemfile::certs(&mut Cursor::new(identity.cert))
+pub(crate) fn convert_certificate_to_pki_types(
+    certificate: &Certificate,
+) -> Result<Vec<CertificateDer<'static>>, TlsError> {
+    rustls_pemfile::certs(&mut Cursor::new(certificate))
         .collect::<Result<Vec<_>, _>>()
-        .map_err(|_| TlsError::CertificateParseError)?;
+        .map_err(|_| TlsError::CertificateParseError)
+}
 
-    let Ok(Some(key)) = rustls_pemfile::private_key(&mut Cursor::new(identity.key)) else {
+pub(crate) fn convert_identity_to_pki_types(
+    identity: &Identity,
+) -> Result<(Vec<CertificateDer<'static>>, PrivateKeyDer<'static>), TlsError> {
+    let cert = convert_certificate_to_pki_types(&identity.cert)?;
+    let Ok(Some(key)) = rustls_pemfile::private_key(&mut Cursor::new(&identity.key)) else {
         return Err(TlsError::PrivateKeyParseError);
     };
-
     Ok((cert, key))
 }
-
-pub(crate) fn add_certs_from_pem(
-    mut certs: &mut dyn std::io::BufRead,
-    roots: &mut RootCertStore,
-) -> Result<(), crate::BoxError> {
-    for cert in rustls_pemfile::certs(&mut certs).collect::<Result<Vec<_>, _>>()? {
-        roots
-            .add(cert)
-            .map_err(|_| TlsError::CertificateParseError)?;
-    }
-
-    Ok(())
-}