diff --git a/NBitcoin/BIP174/PSBTInput.cs b/NBitcoin/BIP174/PSBTInput.cs
index 00891632a..15362e8b0 100644
--- a/NBitcoin/BIP174/PSBTInput.cs
+++ b/NBitcoin/BIP174/PSBTInput.cs
@@ -5,7 +5,7 @@
 using Newtonsoft.Json;
 using System.IO;
 using NBitcoin.DataEncoders;
-using PartialSigKVMap = System.Collections.Generic.SortedDictionary<NBitcoin.PubKey, NBitcoin.ITransactionSignature>;
+using PartialSigKVMap = System.Collections.Generic.SortedDictionary<NBitcoin.PubKey, NBitcoin.TransactionSignature>;
 using System.Diagnostics.CodeAnalysis;
 using NBitcoin.Crypto;
 using System.Text;
@@ -1094,12 +1094,8 @@ internal void Sign(KeyPair keyPair, SigningOptions? signingOptions)
 #endif
 				CheckCompatibleSigHash(sigHash);
 				var signature = PartialSigs[ecdsapk];
-#if HAS_SPAN
-				var existingSigHash = existingSig is TaprootSignature ts ? (uint)ts.SigHash :
-									  (uint)((TransactionSignature)existingSig).SigHash;
-#else
-				var existingSigHash = (uint)((TransactionSignature)existingSig).SigHash;
-#endif
+
+				var existingSigHash = (uint)existingSig.SigHash;
 				if (Transaction is IHasForkId)
 					existingSigHash = existingSigHash & ~(0x40u);
 				if (!SameSigHash(existingSigHash, sigHash))
diff --git a/NBitcoin/BuilderExtensions/P2MultiSigBuilderExtension.cs b/NBitcoin/BuilderExtensions/P2MultiSigBuilderExtension.cs
index 19a6f8e9d..6ced87ec4 100644
--- a/NBitcoin/BuilderExtensions/P2MultiSigBuilderExtension.cs
+++ b/NBitcoin/BuilderExtensions/P2MultiSigBuilderExtension.cs
@@ -78,7 +78,7 @@ public override void Finalize(InputSigningContext inputSigningContext)
 			var multiSigParams = PayToMultiSigTemplate.Instance.ExtractScriptPubKeyParameters(scriptPubKey)!;
 			if (multiSigParams.SignatureCount > txIn.PartialSigs.Count)
 				return;
-			List<ITransactionSignature> sigs = new List<ITransactionSignature>();
+			List<TransactionSignature> sigs = new List<TransactionSignature>();
 			int sigcount = 0;
 			foreach (var pk in multiSigParams.PubKeys)
 			{
@@ -185,7 +185,7 @@ public override void MergePartialSignatures(InputSigningContext inputSigningCont
 			var txIn = inputSigningContext.Input;
 			var scriptPubKey = inputSigningContext.Coin.GetScriptCode();
 
-			var sigs = new ITransactionSignature?[multiSigParams.PubKeys.Length];
+			var sigs = new TransactionSignature?[multiSigParams.PubKeys.Length];
 			int sigCount = 0;
 			for (int i = 0; i < multiSigParams.PubKeys.Length; i++)
 			{
diff --git a/NBitcoin/StandardScriptTemplate.cs b/NBitcoin/StandardScriptTemplate.cs
index 1bfb33c8f..51442303d 100644
--- a/NBitcoin/StandardScriptTemplate.cs
+++ b/NBitcoin/StandardScriptTemplate.cs
@@ -380,12 +380,12 @@ protected override bool CheckScriptSigCore(Script scriptSig, Op[] scriptSigOps,
 			}
 		}
 
-		public Script GenerateScriptSig(ITransactionSignature[] signatures)
+		public Script GenerateScriptSig(TransactionSignature[] signatures)
 		{
-			return GenerateScriptSig((IEnumerable<ITransactionSignature>)signatures);
+			return GenerateScriptSig((IEnumerable<TransactionSignature>)signatures);
 		}
 
-		public Script GenerateScriptSig(IEnumerable<ITransactionSignature> signatures)
+		public Script GenerateScriptSig(IEnumerable<TransactionSignature> signatures)
 		{
 			List<Op> ops = new List<Op>();
 			ops.Add(OpcodeType.OP_0);
@@ -604,7 +604,7 @@ public Script GenerateScriptSig(ECDSASignature signature)
 		{
 			return GenerateScriptSig(new TransactionSignature(signature, SigHash.All));
 		}
-		public Script GenerateScriptSig(ITransactionSignature signature)
+		public Script GenerateScriptSig(TransactionSignature signature)
 		{
 			return new Script(
 				Op.GetPushOp(signature.ToBytes())
@@ -803,7 +803,7 @@ public Script GenerateScriptPubKey(KeyId pubkeyHash)
 				);
 		}
 
-		public Script GenerateScriptSig(ITransactionSignature? signature, PubKey publicKey)
+		public Script GenerateScriptSig(TransactionSignature? signature, PubKey publicKey)
 		{
 			if (publicKey == null)
 				throw new ArgumentNullException(nameof(publicKey));