diff --git a/der/src/asn1/oid.rs b/der/src/asn1/oid.rs
index 3b0e5050b..fbfa71e69 100644
--- a/der/src/asn1/oid.rs
+++ b/der/src/asn1/oid.rs
@@ -4,27 +4,27 @@ use crate::{
     DecodeValue, EncodeValue, Error, FixedTag, Header, Length, Reader, Result, Tag, Tagged, Writer,
     asn1::AnyRef, ord::OrdIsValueOrd,
 };
-use const_oid::ObjectIdentifier;
+use const_oid::{ObjectIdentifier, ObjectIdentifierRef};
 
 #[cfg(feature = "alloc")]
 use super::Any;
 
-impl<'a> DecodeValue<'a> for ObjectIdentifier {
+impl<'a, const MAX_SIZE: usize> DecodeValue<'a> for ObjectIdentifier<MAX_SIZE> {
     type Error = Error;
 
     fn decode_value<R: Reader<'a>>(reader: &mut R, header: Header) -> Result<Self> {
-        let mut buf = [0u8; ObjectIdentifier::MAX_SIZE];
+        let mut buf = [0u8; MAX_SIZE];
         let slice = buf
             .get_mut(..header.length.try_into()?)
             .ok_or_else(|| Self::TAG.length_error())?;
 
         let actual_len = reader.read_into(slice)?.len();
         debug_assert_eq!(actual_len, header.length.try_into()?);
-        Ok(Self::from_bytes(slice)?)
+        Ok(ObjectIdentifierRef::from_bytes(slice)?.try_into()?)
     }
 }
 
-impl EncodeValue for ObjectIdentifier {
+impl<const MAX_SIZE: usize> EncodeValue for ObjectIdentifier<MAX_SIZE> {
     fn value_len(&self) -> Result<Length> {
         Length::try_from(self.as_bytes().len())
     }
@@ -34,14 +34,14 @@ impl EncodeValue for ObjectIdentifier {
     }
 }
 
-impl FixedTag for ObjectIdentifier {
+impl<const MAX_SIZE: usize> FixedTag for ObjectIdentifier<MAX_SIZE> {
     const TAG: Tag = Tag::ObjectIdentifier;
 }
 
-impl OrdIsValueOrd for ObjectIdentifier {}
+impl<const MAX_SIZE: usize> OrdIsValueOrd for ObjectIdentifier<MAX_SIZE> {}
 
-impl<'a> From<&'a ObjectIdentifier> for AnyRef<'a> {
-    fn from(oid: &'a ObjectIdentifier) -> AnyRef<'a> {
+impl<'a, const MAX_SIZE: usize> From<&'a ObjectIdentifier<MAX_SIZE>> for AnyRef<'a> {
+    fn from(oid: &'a ObjectIdentifier<MAX_SIZE>) -> AnyRef<'a> {
         // Note: ensuring an infallible conversion is possible relies on the
         // invariant that `const_oid::MAX_LEN <= Length::max()`.
         //
@@ -56,18 +56,18 @@ impl<'a> From<&'a ObjectIdentifier> for AnyRef<'a> {
 }
 
 #[cfg(feature = "alloc")]
-impl From<ObjectIdentifier> for Any {
-    fn from(oid: ObjectIdentifier) -> Any {
+impl<const MAX_SIZE: usize> From<ObjectIdentifier<MAX_SIZE>> for Any {
+    fn from(oid: ObjectIdentifier<MAX_SIZE>) -> Any {
         AnyRef::from(&oid).into()
     }
 }
 
-impl TryFrom<AnyRef<'_>> for ObjectIdentifier {
+impl<const MAX_SIZE: usize> TryFrom<AnyRef<'_>> for ObjectIdentifier<MAX_SIZE> {
     type Error = Error;
 
-    fn try_from(any: AnyRef<'_>) -> Result<ObjectIdentifier> {
+    fn try_from(any: AnyRef<'_>) -> Result<ObjectIdentifier<MAX_SIZE>> {
         any.tag().assert_eq(Tag::ObjectIdentifier)?;
-        Ok(ObjectIdentifier::from_bytes(any.value())?)
+        Ok(ObjectIdentifierRef::from_bytes(any.value())?.try_into()?)
     }
 }
 
diff --git a/x509-cert/tests/certificate.rs b/x509-cert/tests/certificate.rs
index bd4c73b9b..ba2b74e85 100644
--- a/x509-cert/tests/certificate.rs
+++ b/x509-cert/tests/certificate.rs
@@ -166,7 +166,7 @@ fn reencode_cert() {
 
 #[test]
 fn decode_oversized_oids() {
-    let o1parse = ObjectIdentifier::from_der(&hex!(
+    let o1parse: ObjectIdentifier = Decode::from_der(&hex!(
         "06252B060104018237150885C8B86B87AFF00383A99F3C96C34081ADE6494D82B0E91D85B2873D"
     ))
     .unwrap();