diff --git a/src/rpc/rawtransaction.cpp b/src/rpc/rawtransaction.cpp
index 634be2f7fb9..ce71c052abc 100644
--- a/src/rpc/rawtransaction.cpp
+++ b/src/rpc/rawtransaction.cpp
@@ -785,7 +785,7 @@ static RPCHelpMan signrawtransactionwithkey()
         throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "TX decode failed. Make sure the tx has at least one input.");
     }
 
-    FillableSigningProvider keystore;
+    FlatSigningProvider keystore;
     const UniValue& keys = request.params[1].get_array();
     for (unsigned int idx = 0; idx < keys.size(); ++idx) {
         UniValue k = keys[idx];
@@ -793,7 +793,11 @@ static RPCHelpMan signrawtransactionwithkey()
         if (!key.IsValid()) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Invalid private key");
         }
-        keystore.AddKey(key);
+
+        CPubKey pubkey = key.GetPubKey();
+        CKeyID key_id = pubkey.GetID();
+        keystore.pubkeys.emplace(key_id, pubkey);
+        keystore.keys.emplace(key_id, key);
     }
 
     // Fetch previous transactions (inputs):
diff --git a/src/rpc/rawtransaction_util.cpp b/src/rpc/rawtransaction_util.cpp
index a9e11622a7a..a27e1be5446 100644
--- a/src/rpc/rawtransaction_util.cpp
+++ b/src/rpc/rawtransaction_util.cpp
@@ -181,7 +181,7 @@ static void TxInErrorToJSON(const CTxIn& txin, UniValue& vErrorsRet, const std::
     vErrorsRet.push_back(entry);
 }
 
-void ParsePrevouts(const UniValue& prevTxsUnival, FillableSigningProvider* keystore, std::map<COutPoint, Coin>& coins)
+void ParsePrevouts(const UniValue& prevTxsUnival, FlatSigningProvider* keystore, std::map<COutPoint, Coin>& coins)
 {
     if (!prevTxsUnival.isNull()) {
         const UniValue& prevTxs = prevTxsUnival.get_array();
@@ -247,11 +247,11 @@ void ParsePrevouts(const UniValue& prevTxsUnival, FillableSigningProvider* keyst
                 // work from witnessScript when possible
                 std::vector<unsigned char> scriptData(!ws.isNull() ? ParseHexV(ws, "witnessScript") : ParseHexV(rs, "redeemScript"));
                 CScript script(scriptData.begin(), scriptData.end());
-                keystore->AddCScript(script);
+                keystore->scripts.emplace(CScriptID(script), script);
                 // Automatically also add the P2WSH wrapped version of the script (to deal with P2SH-P2WSH).
                 // This is done for redeemScript only for compatibility, it is encouraged to use the explicit witnessScript field instead.
                 CScript witness_output_script{GetScriptForDestination(WitnessV0ScriptHash(script))};
-                keystore->AddCScript(witness_output_script);
+                keystore->scripts.emplace(CScriptID(witness_output_script), witness_output_script);
 
                 if (!ws.isNull() && !rs.isNull()) {
                     // if both witnessScript and redeemScript are provided,
diff --git a/src/rpc/rawtransaction_util.h b/src/rpc/rawtransaction_util.h
index 964d0b095b1..40d6bbba873 100644
--- a/src/rpc/rawtransaction_util.h
+++ b/src/rpc/rawtransaction_util.h
@@ -12,7 +12,7 @@
 #include <optional>
 
 struct bilingual_str;
-class FillableSigningProvider;
+struct FlatSigningProvider;
 class UniValue;
 struct CMutableTransaction;
 class Coin;
@@ -38,7 +38,7 @@ void SignTransactionResultToJSON(CMutableTransaction& mtx, bool complete, const
   * @param  keystore      A pointer to the temporary keystore if there is one
   * @param  coins         Map of unspent outputs - coins in mempool and current chain UTXO set, may be extended by previous txns outputs after call
   */
-void ParsePrevouts(const UniValue& prevTxsUnival, FillableSigningProvider* keystore, std::map<COutPoint, Coin>& coins);
+void ParsePrevouts(const UniValue& prevTxsUnival, FlatSigningProvider* keystore, std::map<COutPoint, Coin>& coins);
 
 /** Normalize univalue-represented inputs and add them to the transaction */
 void AddInputs(CMutableTransaction& rawTx, const UniValue& inputs_in, bool rbf);