diff --git a/lnrpc/signrpc/signer.proto b/lnrpc/signrpc/signer.proto
index 9085c6f67..07e2db3b1 100644
--- a/lnrpc/signrpc/signer.proto
+++ b/lnrpc/signrpc/signer.proto
@@ -22,8 +22,8 @@ service Signer {
     /*
     ComputeInputScript generates a complete InputIndex for the passed
     transaction with the signature as defined within the passed SignDescriptor.
-    This method should be capable of generating the proper input script for
-    both regular p2wkh output and p2wkh outputs nested within a regular p2sh
+    This method should be capable of generating the proper input script for both
+    regular p2wkh/p2tr outputs and p2wkh outputs nested within a regular p2sh
     output.
 
     Note that when using this method to sign inputs belonging to the wallet,
diff --git a/lnrpc/signrpc/signer.swagger.json b/lnrpc/signrpc/signer.swagger.json
index edd0afa2e..5a7a424a9 100644
--- a/lnrpc/signrpc/signer.swagger.json
+++ b/lnrpc/signrpc/signer.swagger.json
@@ -18,7 +18,7 @@
   "paths": {
     "/v2/signer/inputscript": {
       "post": {
-        "summary": "ComputeInputScript generates a complete InputIndex for the passed\ntransaction with the signature as defined within the passed SignDescriptor.\nThis method should be capable of generating the proper input script for\nboth regular p2wkh output and p2wkh outputs nested within a regular p2sh\noutput.",
+        "summary": "ComputeInputScript generates a complete InputIndex for the passed\ntransaction with the signature as defined within the passed SignDescriptor.\nThis method should be capable of generating the proper input script for both\nregular p2wkh/p2tr outputs and p2wkh outputs nested within a regular p2sh\noutput.",
         "description": "Note that when using this method to sign inputs belonging to the wallet,\nthe only items of the SignDescriptor that need to be populated are pkScript\nin the TxOut field, the value in that same field, and finally the input\nindex.",
         "operationId": "Signer_ComputeInputScript",
         "responses": {
diff --git a/lnrpc/signrpc/signer_grpc.pb.go b/lnrpc/signrpc/signer_grpc.pb.go
index 2c0a01899..e8017b4a8 100644
--- a/lnrpc/signrpc/signer_grpc.pb.go
+++ b/lnrpc/signrpc/signer_grpc.pb.go
@@ -31,8 +31,8 @@ type SignerClient interface {
 	//
 	//ComputeInputScript generates a complete InputIndex for the passed
 	//transaction with the signature as defined within the passed SignDescriptor.
-	//This method should be capable of generating the proper input script for
-	//both regular p2wkh output and p2wkh outputs nested within a regular p2sh
+	//This method should be capable of generating the proper input script for both
+	//regular p2wkh/p2tr outputs and p2wkh outputs nested within a regular p2sh
 	//output.
 	//
 	//Note that when using this method to sign inputs belonging to the wallet,
@@ -255,8 +255,8 @@ type SignerServer interface {
 	//
 	//ComputeInputScript generates a complete InputIndex for the passed
 	//transaction with the signature as defined within the passed SignDescriptor.
-	//This method should be capable of generating the proper input script for
-	//both regular p2wkh output and p2wkh outputs nested within a regular p2sh
+	//This method should be capable of generating the proper input script for both
+	//regular p2wkh/p2tr outputs and p2wkh outputs nested within a regular p2sh
 	//output.
 	//
 	//Note that when using this method to sign inputs belonging to the wallet,
diff --git a/lnrpc/signrpc/signer_server.go b/lnrpc/signrpc/signer_server.go
index 7dbdece22..b71d14f4a 100644
--- a/lnrpc/signrpc/signer_server.go
+++ b/lnrpc/signrpc/signer_server.go
@@ -489,7 +489,8 @@ func (s *Server) SignOutputRaw(_ context.Context, in *SignReq) (*SignResp,
 // ComputeInputScript generates a complete InputIndex for the passed
 // transaction with the signature as defined within the passed SignDescriptor.
 // This method should be capable of generating the proper input script for both
-// regular p2wkh output and p2wkh outputs nested within a regular p2sh output.
+// regular p2wkh/p2tr outputs and p2wkh outputs nested within a regular p2sh
+// output.
 //
 // Note that when using this method to sign inputs belonging to the wallet, the
 // only items of the SignDescriptor that need to be populated are pkScript in
@@ -519,7 +520,33 @@ func (s *Server) ComputeInputScript(ctx context.Context,
 		return nil, fmt.Errorf("unable to decode tx: %v", err)
 	}
 
-	sigHashCache := input.NewTxSigHashesV0Only(&txToSign)
+	var (
+		sigHashCache      = input.NewTxSigHashesV0Only(&txToSign)
+		prevOutputFetcher = txscript.NewMultiPrevOutFetcher(nil)
+	)
+
+	// If we're spending one or more SegWit v1 (Taproot) inputs, then we
+	// need the full UTXO information available.
+	if len(in.PrevOutputs) > 0 {
+		if len(in.PrevOutputs) != len(txToSign.TxIn) {
+			return nil, fmt.Errorf("provided previous outputs " +
+				"doesn't match number of transaction inputs")
+		}
+
+		// Add all previous inputs to our sighash prev out fetcher so we
+		// can calculate the sighash correctly.
+		for idx, txIn := range txToSign.TxIn {
+			prevOutputFetcher.AddPrevOut(
+				txIn.PreviousOutPoint, &wire.TxOut{
+					Value:    in.PrevOutputs[idx].Value,
+					PkScript: in.PrevOutputs[idx].PkScript,
+				},
+			)
+		}
+		sigHashCache = txscript.NewTxSigHashes(
+			&txToSign, prevOutputFetcher,
+		)
+	}
 
 	signDescs := make([]*input.SignDescriptor, 0, len(in.SignDescs))
 	for _, signDesc := range in.SignDescs {
@@ -532,9 +559,10 @@ func (s *Server) ComputeInputScript(ctx context.Context,
 				Value:    signDesc.Output.Value,
 				PkScript: signDesc.Output.PkScript,
 			},
-			HashType:   txscript.SigHashType(signDesc.Sighash),
-			SigHashes:  sigHashCache,
-			InputIndex: int(signDesc.InputIndex),
+			HashType:          txscript.SigHashType(signDesc.Sighash),
+			SigHashes:         sigHashCache,
+			PrevOutputFetcher: prevOutputFetcher,
+			InputIndex:        int(signDesc.InputIndex),
 		})
 	}