diff --git a/api/hashes/all-features.txt b/api/hashes/all-features.txt
index 6a776f228..b860a654d 100644
--- a/api/hashes/all-features.txt
+++ b/api/hashes/all-features.txt
@@ -458,10 +458,10 @@ impl<T: bitcoin_hashes::GeneralHash> bitcoin_hashes::GeneralHash for bitcoin_has
 impl<T: bitcoin_hashes::GeneralHash> bitcoin_hashes::Hash for bitcoin_hashes::hmac::Hmac<T>
 impl<T: bitcoin_hashes::GeneralHash> bitcoin_hashes::HashEngine for bitcoin_hashes::hmac::HmacEngine<T>
 impl<T: bitcoin_hashes::GeneralHash> bitcoin_hashes::hkdf::Hkdf<T> where <T as bitcoin_hashes::GeneralHash>::Engine: core::default::Default
+impl<T: bitcoin_hashes::GeneralHash> bitcoin_hashes::hmac::Hmac<T>
 impl<T: bitcoin_hashes::GeneralHash> bitcoin_hashes::hmac::HmacEngine<T>
 impl<T: bitcoin_hashes::GeneralHash> bitcoin_io::Write for bitcoin_hashes::hmac::HmacEngine<T>
 impl<T: bitcoin_hashes::GeneralHash> core::convert::AsRef<[u8]> for bitcoin_hashes::hmac::Hmac<T>
-impl<T: bitcoin_hashes::GeneralHash> core::default::Default for bitcoin_hashes::hmac::HmacEngine<T> where <T as bitcoin_hashes::GeneralHash>::Engine: core::default::Default
 impl<T: bitcoin_hashes::GeneralHash> core::marker::StructuralPartialEq for bitcoin_hashes::hmac::Hmac<T>
 impl<T: bitcoin_hashes::GeneralHash> std::io::Write for bitcoin_hashes::hmac::HmacEngine<T>
 impl<T: bitcoin_hashes::sha256t::Tag> bitcoin_hashes::GeneralHash for bitcoin_hashes::sha256t::Hash<T>
@@ -669,6 +669,7 @@ pub fn bitcoin_hashes::hmac::Hmac<T>::as_ref(&self) -> &[u8]
 pub fn bitcoin_hashes::hmac::Hmac<T>::clone(&self) -> bitcoin_hashes::hmac::Hmac<T>
 pub fn bitcoin_hashes::hmac::Hmac<T>::cmp(&self, other: &bitcoin_hashes::hmac::Hmac<T>) -> core::cmp::Ordering
 pub fn bitcoin_hashes::hmac::Hmac<T>::deserialize<D: serde::de::Deserializer<'de>>(d: D) -> core::result::Result<bitcoin_hashes::hmac::Hmac<T>, <D as serde::de::Deserializer>::Error>
+pub fn bitcoin_hashes::hmac::Hmac<T>::engine(key: &[u8]) -> bitcoin_hashes::hmac::HmacEngine<T> where <T as bitcoin_hashes::GeneralHash>::Engine: core::default::Default
 pub fn bitcoin_hashes::hmac::Hmac<T>::eq(&self, other: &bitcoin_hashes::hmac::Hmac<T>) -> bool
 pub fn bitcoin_hashes::hmac::Hmac<T>::fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result
 pub fn bitcoin_hashes::hmac::Hmac<T>::from_byte_array(bytes: <T as bitcoin_hashes::Hash>::Bytes) -> Self
@@ -680,7 +681,6 @@ pub fn bitcoin_hashes::hmac::Hmac<T>::partial_cmp(&self, other: &bitcoin_hashes:
 pub fn bitcoin_hashes::hmac::Hmac<T>::serialize<S: serde::ser::Serializer>(&self, s: S) -> core::result::Result<<S as serde::ser::Serializer>::Ok, <S as serde::ser::Serializer>::Error>
 pub fn bitcoin_hashes::hmac::Hmac<T>::to_byte_array(self) -> Self::Bytes
 pub fn bitcoin_hashes::hmac::HmacEngine<T>::clone(&self) -> bitcoin_hashes::hmac::HmacEngine<T>
-pub fn bitcoin_hashes::hmac::HmacEngine<T>::default() -> Self
 pub fn bitcoin_hashes::hmac::HmacEngine<T>::flush(&mut self) -> bitcoin_io::Result<()>
 pub fn bitcoin_hashes::hmac::HmacEngine<T>::flush(&mut self) -> std::io::error::Result<()>
 pub fn bitcoin_hashes::hmac::HmacEngine<T>::from_inner_engines(iengine: <T as bitcoin_hashes::GeneralHash>::Engine, oengine: <T as bitcoin_hashes::GeneralHash>::Engine) -> bitcoin_hashes::hmac::HmacEngine<T>
diff --git a/api/hashes/alloc-only.txt b/api/hashes/alloc-only.txt
index 35bf80f4d..2000ca4f6 100644
--- a/api/hashes/alloc-only.txt
+++ b/api/hashes/alloc-only.txt
@@ -416,9 +416,9 @@ impl<T: bitcoin_hashes::GeneralHash> bitcoin_hashes::GeneralHash for bitcoin_has
 impl<T: bitcoin_hashes::GeneralHash> bitcoin_hashes::Hash for bitcoin_hashes::hmac::Hmac<T>
 impl<T: bitcoin_hashes::GeneralHash> bitcoin_hashes::HashEngine for bitcoin_hashes::hmac::HmacEngine<T>
 impl<T: bitcoin_hashes::GeneralHash> bitcoin_hashes::hkdf::Hkdf<T> where <T as bitcoin_hashes::GeneralHash>::Engine: core::default::Default
+impl<T: bitcoin_hashes::GeneralHash> bitcoin_hashes::hmac::Hmac<T>
 impl<T: bitcoin_hashes::GeneralHash> bitcoin_hashes::hmac::HmacEngine<T>
 impl<T: bitcoin_hashes::GeneralHash> core::convert::AsRef<[u8]> for bitcoin_hashes::hmac::Hmac<T>
-impl<T: bitcoin_hashes::GeneralHash> core::default::Default for bitcoin_hashes::hmac::HmacEngine<T> where <T as bitcoin_hashes::GeneralHash>::Engine: core::default::Default
 impl<T: bitcoin_hashes::GeneralHash> core::marker::StructuralPartialEq for bitcoin_hashes::hmac::Hmac<T>
 impl<T: bitcoin_hashes::sha256t::Tag> bitcoin_hashes::GeneralHash for bitcoin_hashes::sha256t::Hash<T>
 impl<T: bitcoin_hashes::sha256t::Tag> bitcoin_hashes::Hash for bitcoin_hashes::sha256t::Hash<T>
@@ -598,6 +598,7 @@ pub fn bitcoin_hashes::hmac::Hmac<T>::as_byte_array(&self) -> &Self::Bytes
 pub fn bitcoin_hashes::hmac::Hmac<T>::as_ref(&self) -> &[u8]
 pub fn bitcoin_hashes::hmac::Hmac<T>::clone(&self) -> bitcoin_hashes::hmac::Hmac<T>
 pub fn bitcoin_hashes::hmac::Hmac<T>::cmp(&self, other: &bitcoin_hashes::hmac::Hmac<T>) -> core::cmp::Ordering
+pub fn bitcoin_hashes::hmac::Hmac<T>::engine(key: &[u8]) -> bitcoin_hashes::hmac::HmacEngine<T> where <T as bitcoin_hashes::GeneralHash>::Engine: core::default::Default
 pub fn bitcoin_hashes::hmac::Hmac<T>::eq(&self, other: &bitcoin_hashes::hmac::Hmac<T>) -> bool
 pub fn bitcoin_hashes::hmac::Hmac<T>::fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result
 pub fn bitcoin_hashes::hmac::Hmac<T>::from_byte_array(bytes: <T as bitcoin_hashes::Hash>::Bytes) -> Self
@@ -608,7 +609,6 @@ pub fn bitcoin_hashes::hmac::Hmac<T>::hash<__H: core::hash::Hasher>(&self, state
 pub fn bitcoin_hashes::hmac::Hmac<T>::partial_cmp(&self, other: &bitcoin_hashes::hmac::Hmac<T>) -> core::option::Option<core::cmp::Ordering>
 pub fn bitcoin_hashes::hmac::Hmac<T>::to_byte_array(self) -> Self::Bytes
 pub fn bitcoin_hashes::hmac::HmacEngine<T>::clone(&self) -> bitcoin_hashes::hmac::HmacEngine<T>
-pub fn bitcoin_hashes::hmac::HmacEngine<T>::default() -> Self
 pub fn bitcoin_hashes::hmac::HmacEngine<T>::from_inner_engines(iengine: <T as bitcoin_hashes::GeneralHash>::Engine, oengine: <T as bitcoin_hashes::GeneralHash>::Engine) -> bitcoin_hashes::hmac::HmacEngine<T>
 pub fn bitcoin_hashes::hmac::HmacEngine<T>::input(&mut self, buf: &[u8])
 pub fn bitcoin_hashes::hmac::HmacEngine<T>::n_bytes_hashed(&self) -> u64
diff --git a/api/hashes/no-features.txt b/api/hashes/no-features.txt
index cd19b4663..8ac99fc5d 100644
--- a/api/hashes/no-features.txt
+++ b/api/hashes/no-features.txt
@@ -380,9 +380,9 @@ impl<T: bitcoin_hashes::GeneralHash> bitcoin_hashes::GeneralHash for bitcoin_has
 impl<T: bitcoin_hashes::GeneralHash> bitcoin_hashes::Hash for bitcoin_hashes::hmac::Hmac<T>
 impl<T: bitcoin_hashes::GeneralHash> bitcoin_hashes::HashEngine for bitcoin_hashes::hmac::HmacEngine<T>
 impl<T: bitcoin_hashes::GeneralHash> bitcoin_hashes::hkdf::Hkdf<T> where <T as bitcoin_hashes::GeneralHash>::Engine: core::default::Default
+impl<T: bitcoin_hashes::GeneralHash> bitcoin_hashes::hmac::Hmac<T>
 impl<T: bitcoin_hashes::GeneralHash> bitcoin_hashes::hmac::HmacEngine<T>
 impl<T: bitcoin_hashes::GeneralHash> core::convert::AsRef<[u8]> for bitcoin_hashes::hmac::Hmac<T>
-impl<T: bitcoin_hashes::GeneralHash> core::default::Default for bitcoin_hashes::hmac::HmacEngine<T> where <T as bitcoin_hashes::GeneralHash>::Engine: core::default::Default
 impl<T: bitcoin_hashes::GeneralHash> core::marker::StructuralPartialEq for bitcoin_hashes::hmac::Hmac<T>
 impl<T: bitcoin_hashes::sha256t::Tag> bitcoin_hashes::GeneralHash for bitcoin_hashes::sha256t::Hash<T>
 impl<T: bitcoin_hashes::sha256t::Tag> bitcoin_hashes::Hash for bitcoin_hashes::sha256t::Hash<T>
@@ -555,6 +555,7 @@ pub fn bitcoin_hashes::hmac::Hmac<T>::as_byte_array(&self) -> &Self::Bytes
 pub fn bitcoin_hashes::hmac::Hmac<T>::as_ref(&self) -> &[u8]
 pub fn bitcoin_hashes::hmac::Hmac<T>::clone(&self) -> bitcoin_hashes::hmac::Hmac<T>
 pub fn bitcoin_hashes::hmac::Hmac<T>::cmp(&self, other: &bitcoin_hashes::hmac::Hmac<T>) -> core::cmp::Ordering
+pub fn bitcoin_hashes::hmac::Hmac<T>::engine(key: &[u8]) -> bitcoin_hashes::hmac::HmacEngine<T> where <T as bitcoin_hashes::GeneralHash>::Engine: core::default::Default
 pub fn bitcoin_hashes::hmac::Hmac<T>::eq(&self, other: &bitcoin_hashes::hmac::Hmac<T>) -> bool
 pub fn bitcoin_hashes::hmac::Hmac<T>::fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result
 pub fn bitcoin_hashes::hmac::Hmac<T>::from_byte_array(bytes: <T as bitcoin_hashes::Hash>::Bytes) -> Self
@@ -565,7 +566,6 @@ pub fn bitcoin_hashes::hmac::Hmac<T>::hash<__H: core::hash::Hasher>(&self, state
 pub fn bitcoin_hashes::hmac::Hmac<T>::partial_cmp(&self, other: &bitcoin_hashes::hmac::Hmac<T>) -> core::option::Option<core::cmp::Ordering>
 pub fn bitcoin_hashes::hmac::Hmac<T>::to_byte_array(self) -> Self::Bytes
 pub fn bitcoin_hashes::hmac::HmacEngine<T>::clone(&self) -> bitcoin_hashes::hmac::HmacEngine<T>
-pub fn bitcoin_hashes::hmac::HmacEngine<T>::default() -> Self
 pub fn bitcoin_hashes::hmac::HmacEngine<T>::from_inner_engines(iengine: <T as bitcoin_hashes::GeneralHash>::Engine, oengine: <T as bitcoin_hashes::GeneralHash>::Engine) -> bitcoin_hashes::hmac::HmacEngine<T>
 pub fn bitcoin_hashes::hmac::HmacEngine<T>::input(&mut self, buf: &[u8])
 pub fn bitcoin_hashes::hmac::HmacEngine<T>::n_bytes_hashed(&self) -> u64