diff --git a/electrum/transaction.py b/electrum/transaction.py
index 46805873a..3e1ff536b 100644
--- a/electrum/transaction.py
+++ b/electrum/transaction.py
@@ -1186,7 +1186,7 @@ class PartialTxInput(TxInput, PSBTSection):
         self.witness_script = None  # type: Optional[bytes]
         self._unknown = {}  # type: Dict[bytes, bytes]
 
-        self.script_descriptor = None  # type: Optional[Descriptor]
+        self._script_descriptor = None  # type: Optional[Descriptor]
         self._trusted_value_sats = None  # type: Optional[int]
         self._trusted_address = None  # type: Optional[str]
         self._is_p2sh_segwit = None  # type: Optional[bool]  # None means unknown
@@ -1225,6 +1225,19 @@ class PartialTxInput(TxInput, PSBTSection):
             return desc.get_all_pubkeys()
         return set()
 
+    @property
+    def script_descriptor(self):
+        return self._script_descriptor
+
+    @script_descriptor.setter
+    def script_descriptor(self, desc: Optional[Descriptor]):
+        self._script_descriptor = desc
+        if desc:
+            if self.redeem_script is None:
+                self.redeem_script = desc.expand().redeem_script
+            if self.witness_script is None:
+                self.witness_script = desc.expand().witness_script
+
     def to_json(self):
         d = super().to_json()
         d.update({
@@ -1537,7 +1550,7 @@ class PartialTxOutput(TxOutput, PSBTSection):
         self.bip32_paths = {}  # type: Dict[bytes, Tuple[bytes, Sequence[int]]]  # pubkey -> (xpub_fingerprint, path)
         self._unknown = {}  # type: Dict[bytes, bytes]
 
-        self.script_descriptor = None  # type: Optional[Descriptor]
+        self._script_descriptor = None  # type: Optional[Descriptor]
         self.is_mine = False  # type: bool  # whether the wallet considers the output to be ismine
         self.is_change = False  # type: bool  # whether the wallet considers the output to be change
 
@@ -1547,6 +1560,19 @@ class PartialTxOutput(TxOutput, PSBTSection):
             return desc.get_all_pubkeys()
         return set()
 
+    @property
+    def script_descriptor(self):
+        return self._script_descriptor
+
+    @script_descriptor.setter
+    def script_descriptor(self, desc: Optional[Descriptor]):
+        self._script_descriptor = desc
+        if desc:
+            if self.redeem_script is None:
+                self.redeem_script = desc.expand().redeem_script
+            if self.witness_script is None:
+                self.witness_script = desc.expand().witness_script
+
     def to_json(self):
         d = super().to_json()
         d.update({
diff --git a/electrum/wallet.py b/electrum/wallet.py
index fc62cd3d3..6d0270fef 100644
--- a/electrum/wallet.py
+++ b/electrum/wallet.py
@@ -2197,18 +2197,6 @@ class Abstract_Wallet(ABC, Logger, EventListener):
                 self.lnworker.swap_manager.add_txin_info(txin)
             return
         txin.script_descriptor = self._get_script_descriptor_for_address(address)
-        if txin.redeem_script is None:  # FIXME should be set in transaction.py instead, based on the script desc
-            try:
-                redeem_script_hex = self.get_redeem_script(address)
-                txin.redeem_script = bfh(redeem_script_hex) if redeem_script_hex else None
-            except UnknownTxinType:
-                pass
-        if txin.witness_script is None:  # FIXME should be set in transaction.py instead, based on the script desc
-            try:
-                witness_script_hex = self.get_witness_script(address)
-                txin.witness_script = bfh(witness_script_hex) if witness_script_hex else None
-            except UnknownTxinType:
-                pass
         self._add_txinout_derivation_info(txin, address, only_der_suffix=only_der_suffix)
         txin.block_height = self.adb.get_tx_height(txin.prevout.txid.hex()).height
 
@@ -2295,18 +2283,6 @@ class Abstract_Wallet(ABC, Logger, EventListener):
         txout.is_mine = True
         txout.is_change = self.is_change(address)
         self._add_txinout_derivation_info(txout, address, only_der_suffix=only_der_suffix)
-        if txout.redeem_script is None:  # FIXME should be set in transaction.py instead, based on the script desc
-            try:
-                redeem_script_hex = self.get_redeem_script(address)
-                txout.redeem_script = bfh(redeem_script_hex) if redeem_script_hex else None
-            except UnknownTxinType:
-                pass
-        if txout.witness_script is None:  # FIXME should be set in transaction.py instead, based on the script desc
-            try:
-                witness_script_hex = self.get_witness_script(address)
-                txout.witness_script = bfh(witness_script_hex) if witness_script_hex else None
-            except UnknownTxinType:
-                pass
 
     def sign_transaction(self, tx: Transaction, password) -> Optional[PartialTransaction]:
         if self.is_watching_only():