diff --git a/x509-cert/src/builder.rs b/x509-cert/src/builder.rs
index 29037748d..811d0c5c4 100644
--- a/x509-cert/src/builder.rs
+++ b/x509-cert/src/builder.rs
@@ -15,7 +15,7 @@ use crate::{
     certificate::{self, Certificate, TbsCertificate, Version},
     crl::{CertificateList, RevokedCert, TbsCertList},
     ext::{
-        AsExtension, Extensions,
+        Extensions, ToExtension,
         pkix::{AuthorityKeyIdentifier, CrlNumber, SubjectKeyIdentifier},
     },
     serial_number::SerialNumber,
@@ -216,12 +216,12 @@ where
 
     /// Add an extension to this certificate
     ///
-    /// Extensions need to implement [`AsExtension`], examples may be found in
-    /// in [`AsExtension` documentation](../ext/trait.AsExtension.html#examples) or
-    /// [the implementors](../ext/trait.AsExtension.html#implementors).
-    pub fn add_extension<E: AsExtension>(
+    /// Extensions need to implement [`ToExtension`], examples may be found in
+    /// in [`ToExtension` documentation](../ext/trait.ToExtension.html#examples) or
+    /// [the implementors](../ext/trait.ToExtension.html#implementors).
+    pub fn add_extension<E: ToExtension>(
         &mut self,
-        extension: &E,
+        extension: E,
     ) -> core::result::Result<(), E::Error> {
         let ext = extension.to_extension(&self.tbs.subject, &self.extensions)?;
         self.extensions.push(ext);
diff --git a/x509-cert/src/builder/profile/cabf.rs b/x509-cert/src/builder/profile/cabf.rs
index d69b0c2b1..2b6050376 100644
--- a/x509-cert/src/builder/profile/cabf.rs
+++ b/x509-cert/src/builder/profile/cabf.rs
@@ -8,7 +8,7 @@ use crate::{
     builder::{BuilderProfile, Error, Result},
     certificate::TbsCertificate,
     ext::{
-        AsExtension, Extension,
+        Extension, ToExtension,
         pkix::{
             AuthorityKeyIdentifier, BasicConstraints, KeyUsage, KeyUsages, SubjectKeyIdentifier,
         },
diff --git a/x509-cert/src/builder/profile/cabf/tls.rs b/x509-cert/src/builder/profile/cabf/tls.rs
index 4b28d5544..9cf64a283 100644
--- a/x509-cert/src/builder/profile/cabf/tls.rs
+++ b/x509-cert/src/builder/profile/cabf/tls.rs
@@ -16,7 +16,7 @@ use crate::{
     builder::{BuilderProfile, Result},
     certificate::TbsCertificate,
     ext::{
-        AsExtension, Extension,
+        Extension, ToExtension,
         pkix::{
             AuthorityKeyIdentifier, BasicConstraints, ExtendedKeyUsage, KeyUsage, KeyUsages,
             SubjectKeyIdentifier, name::GeneralNames,
diff --git a/x509-cert/src/builder/profile/devid.rs b/x509-cert/src/builder/profile/devid.rs
index 14582cb6b..0d7e884a5 100644
--- a/x509-cert/src/builder/profile/devid.rs
+++ b/x509-cert/src/builder/profile/devid.rs
@@ -19,7 +19,7 @@ use crate::{
     builder::{BuilderProfile, Result},
     certificate::TbsCertificate,
     ext::{
-        AsExtension, Extension,
+        Extension, ToExtension,
         pkix::{
             AuthorityKeyIdentifier, KeyUsage, KeyUsages, SubjectAltName,
             name::{GeneralName, GeneralNames, HardwareModuleName, OtherName},
diff --git a/x509-cert/src/ext.rs b/x509-cert/src/ext.rs
index 511659304..da92b237d 100644
--- a/x509-cert/src/ext.rs
+++ b/x509-cert/src/ext.rs
@@ -35,6 +35,18 @@ pub struct Extension {
     pub extn_value: OctetString,
 }
 
+impl ToExtension for Extension {
+    type Error = der::Error;
+
+    fn to_extension(
+        self,
+        _subject: &crate::name::Name,
+        _extensions: &[Extension],
+    ) -> Result<Extension, Self::Error> {
+        Ok(self)
+    }
+}
+
 /// Extensions as defined in [RFC 5280 Section 4.1.2.9].
 ///
 /// ```text
@@ -91,44 +103,68 @@ pub trait Criticality {
 ///     }
 /// }
 /// ```
-pub trait AsExtension {
+pub trait ToExtension {
     /// The error type returned when encoding the extension.
     type Error;
 
     /// Returns the Extension with the content encoded.
     fn to_extension(
-        &self,
+        self,
         subject: &crate::name::Name,
         extensions: &[Extension],
     ) -> Result<Extension, Self::Error>;
 }
 
-impl<T: Criticality + AssociatedOid + der::Encode> AsExtension for T {
+impl<T: Criticality + AssociatedOid + der::Encode> ToExtension for &T {
     type Error = der::Error;
 
     fn to_extension(
-        &self,
+        self,
         subject: &crate::name::Name,
         extensions: &[Extension],
     ) -> Result<Extension, Self::Error> {
-        Ok(Extension {
-            extn_id: <Self as AssociatedOid>::OID,
-            critical: self.criticality(subject, extensions),
-            extn_value: OctetString::new(self.to_der()?)?,
-        })
+        let criticality = self.criticality(subject, extensions);
+        (criticality, self).to_extension(subject, extensions)
+    }
+}
+
+impl<T: Criticality + der::Encode> ToExtension for (ObjectIdentifier, &T) {
+    type Error = der::Error;
+
+    fn to_extension(
+        self,
+        subject: &crate::name::Name,
+        extensions: &[Extension],
+    ) -> Result<Extension, Self::Error> {
+        let criticality = self.1.criticality(subject, extensions);
+        (self.0, criticality, self.1).to_extension(subject, extensions)
     }
 }
 
-impl<T: AsExtension> AsExtension for (bool, T) {
-    type Error = T::Error;
+impl<T: AssociatedOid + der::Encode> ToExtension for (bool, &T) {
+    type Error = der::Error;
 
     fn to_extension(
-        &self,
+        self,
         subject: &crate::name::Name,
         extensions: &[Extension],
     ) -> Result<Extension, Self::Error> {
-        let mut extension = self.1.to_extension(subject, extensions)?;
-        extension.critical = self.0;
-        Ok(extension)
+        (T::OID, self.0, self.1).to_extension(subject, extensions)
+    }
+}
+
+impl<T: der::Encode> ToExtension for (ObjectIdentifier, bool, &T) {
+    type Error = der::Error;
+
+    fn to_extension(
+        self,
+        _subject: &crate::name::Name,
+        _extensions: &[Extension],
+    ) -> Result<Extension, Self::Error> {
+        Ok(Extension {
+            extn_id: self.0,
+            critical: self.1,
+            extn_value: OctetString::new(self.2.to_der()?)?,
+        })
     }
 }
diff --git a/x509-cert/src/request/builder.rs b/x509-cert/src/request/builder.rs
index db26fda57..84ae5c96c 100644
--- a/x509-cert/src/request/builder.rs
+++ b/x509-cert/src/request/builder.rs
@@ -8,7 +8,7 @@ use spki::{
 
 use crate::{
     builder::{Builder, Error, NULL_OID, Result},
-    ext::AsExtension,
+    ext::ToExtension,
     name::Name,
     request::{CertReq, CertReqInfo, ExtensionReq, attributes::AsAttribute},
 };
@@ -77,12 +77,12 @@ impl RequestBuilder {
 
     /// Add an extension to this certificate request
     ///
-    /// Extensions need to implement [`AsExtension`], examples may be found in
-    /// in [`AsExtension` documentation](../ext/trait.AsExtension.html#examples) or
-    /// [the implementors](../ext/trait.AsExtension.html#implementors).
-    pub fn add_extension<E: AsExtension>(
+    /// Extensions need to implement [`ToExtension`], examples may be found in
+    /// in [`ToExtension` documentation](../ext/trait.ToExtension.html#examples) or
+    /// [the implementors](../ext/trait.ToExtension.html#implementors).
+    pub fn add_extension<E: ToExtension>(
         &mut self,
-        extension: &E,
+        extension: E,
     ) -> core::result::Result<(), E::Error> {
         let ext = extension.to_extension(&self.info.subject, &self.extension_req.0)?;
 
diff --git a/x509-cert/tests/builder_crl.rs b/x509-cert/tests/builder_crl.rs
index 2a8f81726..41f8ecd41 100644
--- a/x509-cert/tests/builder_crl.rs
+++ b/x509-cert/tests/builder_crl.rs
@@ -17,7 +17,7 @@ use x509_cert::{
     certificate::Rfc5280,
     crl::RevokedCert,
     ext::{
-        AsExtension,
+        ToExtension,
         pkix::{CrlNumber, CrlReason, name::GeneralName},
     },
     name::Name,
diff --git a/x509-ocsp/src/basic.rs b/x509-ocsp/src/basic.rs
index e4dfb72b2..3c3cf2d43 100644
--- a/x509-ocsp/src/basic.rs
+++ b/x509-ocsp/src/basic.rs
@@ -130,7 +130,7 @@ mod builder {
     use const_oid::AssociatedOid;
     use digest::Digest;
     use x509_cert::{
-        Certificate, crl::CertificateList, ext::AsExtension, name::Name,
+        Certificate, crl::CertificateList, ext::ToExtension, name::Name,
         serial_number::SerialNumber,
     };
 
@@ -171,7 +171,7 @@ mod builder {
         /// extension encoding fails.
         ///
         /// [RFC 6960 Section 4.4]: https://datatracker.ietf.org/doc/html/rfc6960#section-4.4
-        pub fn with_extension<E: AsExtension>(mut self, ext: E) -> Result<Self, E::Error> {
+        pub fn with_extension<E: ToExtension>(mut self, ext: E) -> Result<Self, E::Error> {
             let ext = ext.to_extension(&Name::default(), &[])?;
             match self.single_extensions {
                 Some(ref mut exts) => exts.push(ext),
diff --git a/x509-ocsp/src/builder/request.rs b/x509-ocsp/src/builder/request.rs
index 1b9bc54f7..45cb587fd 100644
--- a/x509-ocsp/src/builder/request.rs
+++ b/x509-ocsp/src/builder/request.rs
@@ -9,7 +9,7 @@ use spki::{DynSignatureAlgorithmIdentifier, SignatureBitStringEncoding};
 use x509_cert::{
     Certificate,
     certificate::Rfc5280,
-    ext::{AsExtension, pkix::name::GeneralName},
+    ext::{ToExtension, pkix::name::GeneralName},
     name::Name,
 };
 
@@ -45,7 +45,7 @@ use x509_cert::{
 ///     .with_request(Request::from_issuer::<Sha1>(&issuer, SerialNumber::from(2usize)).unwrap())
 ///     .with_request(Request::from_issuer::<Sha1>(&issuer, SerialNumber::from(3usize)).unwrap())
 ///     .with_request(Request::from_issuer::<Sha1>(&issuer, SerialNumber::from(4usize)).unwrap())
-///     .with_extension(Nonce::generate(&mut rng, 32).unwrap())
+///     .with_extension(&Nonce::generate(&mut rng, 32).unwrap())
 ///     .unwrap()
 ///     .build();
 ///
@@ -53,7 +53,7 @@ use x509_cert::{
 /// let signer_cert_chain = vec![cert.clone()];
 /// let req = OcspRequestBuilder::default()
 ///     .with_request(Request::from_cert::<Sha1>(&issuer, &cert).unwrap())
-///     .with_extension(Nonce::generate(&mut rng, 32).unwrap())
+///     .with_extension(&Nonce::generate(&mut rng, 32).unwrap())
 ///     .unwrap()
 ///     .sign(&mut signer, Some(signer_cert_chain))
 ///     .unwrap();
@@ -96,7 +96,7 @@ impl OcspRequestBuilder {
     /// extension encoding fails.
     ///
     /// [RFC 6960 Section 4.4]: https://datatracker.ietf.org/doc/html/rfc6960#section-4.4
-    pub fn with_extension<E: AsExtension>(mut self, ext: E) -> Result<Self, E::Error> {
+    pub fn with_extension<E: ToExtension>(mut self, ext: E) -> Result<Self, E::Error> {
         let ext = ext.to_extension(&Name::default(), &[])?;
         match self.tbs.request_extensions {
             Some(ref mut exts) => exts.push(ext),
diff --git a/x509-ocsp/src/builder/response.rs b/x509-ocsp/src/builder/response.rs
index 06061ac74..7152418b0 100644
--- a/x509-ocsp/src/builder/response.rs
+++ b/x509-ocsp/src/builder/response.rs
@@ -11,7 +11,7 @@ use signature::{RandomizedSigner, Signer};
 use spki::{DynSignatureAlgorithmIdentifier, SignatureBitStringEncoding};
 use x509_cert::{
     Certificate,
-    ext::{AsExtension, Extensions},
+    ext::{Extensions, ToExtension},
     name::Name,
 };
 
@@ -53,7 +53,7 @@ use x509_cert::{
 ///     );
 ///
 /// if let Some(nonce) = req.nonce() {
-///     builder = builder.with_extension(nonce).unwrap();
+///     builder = builder.with_extension(&nonce).unwrap();
 /// }
 ///
 /// #[cfg(feature = "std")]
@@ -101,7 +101,7 @@ impl OcspResponseBuilder {
     /// extension encoding fails.
     ///
     /// [RFC 6960 Section 4.4]: https://datatracker.ietf.org/doc/html/rfc6960#section-4.4
-    pub fn with_extension<E: AsExtension>(mut self, ext: E) -> Result<Self, E::Error> {
+    pub fn with_extension<E: ToExtension>(mut self, ext: E) -> Result<Self, E::Error> {
         let ext = ext.to_extension(&Name::default(), &[])?;
         match self.response_extensions {
             Some(ref mut exts) => exts.push(ext),
diff --git a/x509-ocsp/src/request.rs b/x509-ocsp/src/request.rs
index 53b67f432..f6a3f71f3 100644
--- a/x509-ocsp/src/request.rs
+++ b/x509-ocsp/src/request.rs
@@ -127,7 +127,7 @@ mod builder {
     use crate::{CertId, Request, builder::Error};
     use const_oid::AssociatedOid;
     use digest::Digest;
-    use x509_cert::{Certificate, ext::AsExtension, name::Name, serial_number::SerialNumber};
+    use x509_cert::{Certificate, ext::ToExtension, name::Name, serial_number::SerialNumber};
 
     impl Request {
         /// Returns a new `Request` with the specified `CertID`
@@ -172,7 +172,7 @@ mod builder {
         /// extension encoding fails.
         ///
         /// [RFC 6960 Section 4.4]: https://datatracker.ietf.org/doc/html/rfc6960#section-4.4
-        pub fn with_extension<E: AsExtension>(mut self, ext: E) -> Result<Self, E::Error> {
+        pub fn with_extension<E: ToExtension>(mut self, ext: E) -> Result<Self, E::Error> {
             let ext = ext.to_extension(&Name::default(), &[])?;
             match self.single_request_extensions {
                 Some(ref mut exts) => exts.push(ext),
diff --git a/x509-ocsp/tests/builder.rs b/x509-ocsp/tests/builder.rs
index fe85c6090..6c91b94a5 100644
--- a/x509-ocsp/tests/builder.rs
+++ b/x509-ocsp/tests/builder.rs
@@ -126,12 +126,12 @@ fn encode_ocsp_req_multiple_extensions() {
         .with_request(
             Request::from_issuer::<Sha1>(&ISSUER, SerialNumber::from(0x10001usize))
                 .unwrap()
-                .with_extension(single_ext1)
+                .with_extension(&single_ext1)
                 .unwrap(),
         )
-        .with_extension(ext1)
+        .with_extension(&ext1)
         .unwrap()
-        .with_extension(ext2)
+        .with_extension(&ext2)
         .unwrap()
         .build();
     assert_eq!(&req.to_der().unwrap(), &req_der);
@@ -296,12 +296,12 @@ fn encode_ocsp_resp_multiple_extensions() {
             .with_next_update(OcspGeneralizedTime::from(
                 DateTime::new(2020, 1, 1, 0, 0, 0).unwrap(),
             ))
-            .with_extension(single_ext1)
+            .with_extension(&single_ext1)
             .unwrap()
-            .with_extension(single_ext2)
+            .with_extension(&single_ext2)
             .unwrap(),
         )
-        .with_extension(ext1)
+        .with_extension(&ext1)
         .unwrap()
         .sign(
             &mut signer,