diff --git a/core-test/src/test/scala/org/bitcoins/core/psbt/PSBTUnitTest.scala b/core-test/src/test/scala/org/bitcoins/core/psbt/PSBTUnitTest.scala
index d930595910..394564db4a 100644
--- a/core-test/src/test/scala/org/bitcoins/core/psbt/PSBTUnitTest.scala
+++ b/core-test/src/test/scala/org/bitcoins/core/psbt/PSBTUnitTest.scala
@@ -348,14 +348,14 @@ class PSBTUnitTest extends BitcoinSAsyncTest {
   }
 
   def dummyTx(
+      prevTxId: DoubleSha256Digest = DoubleSha256Digest.empty,
       scriptSig: ScriptSignature = EmptyScriptSignature,
       spk: ScriptPubKey = EmptyScriptPubKey): Transaction = {
     BaseTransaction(
       version = Int32.zero,
       inputs = Vector(
-        TransactionInput(outPoint =
-                           TransactionOutPoint(txId = DoubleSha256Digest.empty,
-                                               vout = UInt32.zero),
+        TransactionInput(outPoint = TransactionOutPoint(txId = prevTxId,
+                                                        vout = UInt32.zero),
                          scriptSignature = scriptSig,
                          sequenceNumber = UInt32.zero)),
       outputs = Vector(TransactionOutput(CurrencyUnits.oneBTC, spk)),
@@ -364,9 +364,10 @@ class PSBTUnitTest extends BitcoinSAsyncTest {
   }
 
   def dummyPSBT(
+      prevTxId: DoubleSha256Digest = DoubleSha256Digest.empty,
       scriptSig: ScriptSignature = EmptyScriptSignature,
       spk: ScriptPubKey = EmptyScriptPubKey): PSBT = {
-    PSBT.fromUnsignedTx(dummyTx(scriptSig, spk))
+    PSBT.fromUnsignedTx(dummyTx(prevTxId, scriptSig, spk))
   }
 
   it must "successfully change a NonWitnessUTXO to a WitnessUTXO when compressing" in {
@@ -517,4 +518,28 @@ class PSBTUnitTest extends BitcoinSAsyncTest {
       "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")
     assert(psbt.verifyFinalizedInput(0))
   }
+
+  it must "correctly add a non-witness utxo when there is a witness v0 redeem script" in {
+
+    val witScript = P2PKHScriptPubKey(ECPublicKey.freshPublicKey)
+    val witness = P2WSHWitnessV0(witScript)
+    val redeemScript = P2WSHWitnessSPKV0(witScript)
+    val p2sh = P2SHScriptPubKey(redeemScript)
+
+    val utxoTx = dummyTx(spk = p2sh)
+
+    val psbtTx = dummyTx(prevTxId = utxoTx.txId)
+
+    val psbt = PSBT
+      .fromUnsignedTx(psbtTx)
+      .addScriptWitnessToInput(witness, 0)
+      .addRedeemOrWitnessScriptToInput(redeemScript, 0)
+
+    val withUtxo = psbt.addUTXOToInput(utxoTx, 0)
+
+    assert(
+      withUtxo.inputMaps.head.nonWitnessOrUnknownUTXOOpt
+        .map(_.transactionSpent)
+        .contains(utxoTx))
+  }
 }
diff --git a/core/src/main/scala/org/bitcoins/core/psbt/PSBT.scala b/core/src/main/scala/org/bitcoins/core/psbt/PSBT.scala
index 435e8b194c..aa69da5d60 100644
--- a/core/src/main/scala/org/bitcoins/core/psbt/PSBT.scala
+++ b/core/src/main/scala/org/bitcoins/core/psbt/PSBT.scala
@@ -225,8 +225,13 @@ case class PSBT(
           inputMap.redeemScriptOpt.isDefined && WitnessScriptPubKey
             .isWitnessScriptPubKey(
               inputMap.redeemScriptOpt.get.redeemScript.asm)
-        val notBIP143Vulnerable =
-          !out.scriptPubKey.isInstanceOf[WitnessScriptPubKeyV0]
+        val notBIP143Vulnerable = {
+          !out.scriptPubKey.isInstanceOf[WitnessScriptPubKeyV0] && !(
+            hasWitRedeemScript &&
+              inputMap.redeemScriptOpt.get.redeemScript
+                .isInstanceOf[WitnessScriptPubKeyV0]
+          )
+        }
 
         if (
           (outIsWitnessScript || hasWitScript || hasWitRedeemScript) && notBIP143Vulnerable
@@ -369,6 +374,46 @@ case class PSBT(
     PSBT(globalMap, newInputMaps, outputMaps)
   }
 
+  def addFinalizedScriptWitnessToInput(
+      scriptSignature: ScriptSignature,
+      scriptWitness: ScriptWitness,
+      index: Int): PSBT = {
+    require(index >= 0,
+            s"index must be greater than or equal to 0, got: $index")
+    require(
+      index < inputMaps.size,
+      s"index must be less than the number of input maps present in the psbt, $index >= ${inputMaps.size}")
+    require(!inputMaps(index).isFinalized,
+            s"Cannot update an InputPSBTMap that is finalized, index: $index")
+
+    val prevInput = inputMaps(index)
+
+    require(
+      prevInput.elements.forall {
+        case _: NonWitnessOrUnknownUTXO | _: WitnessUTXO | _: Unknown => true
+        case redeemScript: RedeemScript                               =>
+          // RedeemScript is okay if it matches the script signature given
+          redeemScript.redeemScript match {
+            case _: NonWitnessScriptPubKey => false
+            case wspk: WitnessScriptPubKey =>
+              P2SHScriptSignature(wspk) == scriptSignature
+          }
+        case _: InputPSBTRecord => false
+      },
+      s"Input already contains fields: ${prevInput.elements}"
+    )
+
+    val finalizedScripts = Vector(FinalizedScriptSig(scriptSignature),
+                                  FinalizedScriptWitness(scriptWitness))
+
+    // Replace RedeemScripts with FinalizedScriptSignatures and add FinalizedScriptWitnesses
+    val records = prevInput.elements.filterNot(
+      _.isInstanceOf[RedeemScript]) ++ finalizedScripts
+    val newMap = InputPSBTMap(records)
+    val newInputMaps = inputMaps.updated(index, newMap)
+    PSBT(globalMap, newInputMaps, outputMaps)
+  }
+
   /**
     * Adds script to the indexed OutputPSBTMap to either the RedeemScript
     * or WitnessScript field depending on the script and available information in the PSBT
@@ -816,6 +861,30 @@ object PSBT extends Factory[PSBT] with StringFactory[PSBT] {
     PSBT(globalMap, inputMaps, outputMaps)
   }
 
+  def fromUnsignedTxWithP2SHScript(tx: Transaction): PSBT = {
+    val inputs = tx.inputs.toVector
+    val utxInputs = inputs.map { input =>
+      TransactionInput(input.previousOutput,
+                       EmptyScriptSignature,
+                       input.sequence)
+    }
+    val utx = BaseTransaction(tx.version, utxInputs, tx.outputs, tx.lockTime)
+    val psbt = fromUnsignedTx(utx)
+
+    val p2shScriptSigs = inputs
+      .map(_.scriptSignature)
+      .zipWithIndex
+      .collect {
+        case (p2sh: P2SHScriptSignature, index) => (p2sh, index)
+      }
+      .filter(_._1.scriptSignatureNoRedeemScript == EmptyScriptSignature)
+
+    p2shScriptSigs.foldLeft(psbt) {
+      case (psbtSoFar, (p2sh, index)) =>
+        psbtSoFar.addRedeemOrWitnessScriptToInput(p2sh.redeemScript, index)
+    }
+  }
+
   /** Constructs a full (ready to be finalized) but unfinalized PSBT from an
     * unsigned transaction and a SpendingInfoAndNonWitnessTxs
     */