diff --git a/src/interpreter/mod.rs b/src/interpreter/mod.rs
index e2fbaa710..973713cfa 100644
--- a/src/interpreter/mod.rs
+++ b/src/interpreter/mod.rs
@@ -1065,13 +1065,13 @@ mod tests {
         n: usize,
     ) -> (
         Vec<bitcoin::PublicKey>,
-        Vec<Vec<u8>>,
+        Vec<bitcoin::ecdsa::SerializedSignature>,
         Vec<bitcoin::ecdsa::Signature>,
         secp256k1::Message,
         Secp256k1<secp256k1::All>,
         Vec<bitcoin::key::XOnlyPublicKey>,
         Vec<bitcoin::taproot::Signature>,
-        Vec<Vec<u8>>,
+        Vec<bitcoin::taproot::serialized_signature::SerializedSignature>,
     ) {
         let secp = secp256k1::Secp256k1::new();
         let msg = secp256k1::Message::from_digest(*b"Yoda: btc, I trust. HODL I must!");
@@ -1094,14 +1094,13 @@ mod tests {
                 compressed: true,
             };
             let signature = secp.sign_ecdsa(&msg, &sk);
-            ecdsa_sigs.push(bitcoin::ecdsa::Signature {
+            let bitcoin_sig = bitcoin::ecdsa::Signature {
                 signature,
                 sighash_type: bitcoin::sighash::EcdsaSighashType::All,
-            });
-            let mut sigser = signature.serialize_der().to_vec();
-            sigser.push(0x01); // sighash_all
+            };
+            ecdsa_sigs.push(bitcoin_sig);
+            der_sigs.push(bitcoin_sig.serialize());
             pks.push(pk);
-            der_sigs.push(sigser);
 
             let keypair = bitcoin::key::Keypair::from_secret_key(&secp, &sk);
             let (x_only_pk, _parity) = bitcoin::key::XOnlyPublicKey::from_keypair(&keypair);
@@ -1111,7 +1110,7 @@ mod tests {
                 signature: schnorr_sig,
                 sighash_type: bitcoin::sighash::TapSighashType::Default,
             };
-            ser_schnorr_sigs.push(schnorr_sig.to_vec());
+            ser_schnorr_sigs.push(schnorr_sig.serialize());
             schnorr_sigs.push(schnorr_sig);
         }
         (pks, der_sigs, ecdsa_sigs, msg, secp, x_only_pks, schnorr_sigs, ser_schnorr_sigs)
diff --git a/src/plan.rs b/src/plan.rs
index 5177ae82d..c2159ff85 100644
--- a/src/plan.rs
+++ b/src/plan.rs
@@ -148,7 +148,7 @@ where
     }
 
     fn provider_lookup_tap_key_spend_sig(&self, pk: &Pk) -> Option<usize> {
-        Satisfier::lookup_tap_key_spend_sig(self, pk).map(|s| s.to_vec().len())
+        Satisfier::lookup_tap_key_spend_sig(self, pk).map(|s| s.serialize().len())
     }
 
     fn provider_lookup_tap_leaf_script_sig(
@@ -156,7 +156,7 @@ where
         pk: &Pk,
         leaf_hash: &TapLeafHash,
     ) -> Option<usize> {
-        Satisfier::lookup_tap_leaf_script_sig(self, pk, leaf_hash).map(|s| s.to_vec().len())
+        Satisfier::lookup_tap_leaf_script_sig(self, pk, leaf_hash).map(|s| s.serialize().len())
     }
 
     fn provider_lookup_raw_pkh_pk(&self, hash: &hash160::Hash) -> Option<bitcoin::PublicKey> {
@@ -179,7 +179,7 @@ where
         hash: &(hash160::Hash, TapLeafHash),
     ) -> Option<(XOnlyPublicKey, usize)> {
         Satisfier::lookup_raw_pkh_tap_leaf_script_sig(self, hash)
-            .map(|(pk, sig)| (pk, sig.to_vec().len()))
+            .map(|(pk, sig)| (pk, sig.serialize().len()))
     }
 
     fn provider_lookup_sha256(&self, hash: &Pk::Sha256) -> bool {