diff --git a/src/libxrpl/tx/transactors/lending/LoanBrokerSet.cpp b/src/libxrpl/tx/transactors/lending/LoanBrokerSet.cpp
index e291d3c166..7355e2c20f 100644
--- a/src/libxrpl/tx/transactors/lending/LoanBrokerSet.cpp
+++ b/src/libxrpl/tx/transactors/lending/LoanBrokerSet.cpp
@@ -7,6 +7,7 @@
 #include <xrpl/tx/transactors/lending/LendingHelpers.h>
 
 namespace xrpl {
+
 bool
 LoanBrokerSet::checkExtraFeatures(PreflightContext const& ctx)
 {
@@ -97,7 +98,7 @@ LoanBrokerSet::getValueFields()
  * @param id The vault ID to look up.
  * @return The vault SLE on success, or a TER error.
  */
-static Expected<std::shared_ptr<SLE const>, TER>
+[[nodiscard]] static Expected<std::shared_ptr<SLE const>, TER>
 readVault(PreclaimContext const& ctx, AccountID const& account, uint256 const& id)
 {
     auto const sle = ctx.view.read(keylet::vault(id));
@@ -121,7 +122,7 @@ readVault(PreclaimContext const& ctx, AccountID const& account, uint256 const& i
  * @param brokerID The LoanBroker ID to update.
  * @return The vault SLE on success, or a TER error.
  */
-static Expected<std::shared_ptr<SLE const>, TER>
+[[nodiscard]] static Expected<std::shared_ptr<SLE const>, TER>
 preclaimUpdate(PreclaimContext const& ctx, AccountID const& account, uint256 const& brokerID)
 {
     auto const& tx = ctx.tx;
@@ -197,9 +198,12 @@ preclaimUpdate(PreclaimContext const& ctx, AccountID const& account, uint256 con
  * @param account The transaction submitter (vault owner).
  * @return The vault SLE on success, or a TER error.
  */
-static Expected<std::shared_ptr<SLE const>, TER>
+[[nodiscard]] static Expected<std::shared_ptr<SLE const>, TER>
 preclaimCreate(PreclaimContext const& ctx, AccountID const& account)
 {
+    XRPL_ASSERT(
+        ctx.tx.isFieldPresent(sfVaultID),
+        "xrpl::LoanBrokerSet::preclaimCreate : VaultID is present in the transaction");
     auto const vault = readVault(ctx, account, ctx.tx[sfVaultID]);
     if (!vault)
         return vault;
diff --git a/src/test/app/LoanBroker_test.cpp b/src/test/app/LoanBroker_test.cpp
index f05ab1af09..75ff7fb03b 100644
--- a/src/test/app/LoanBroker_test.cpp
+++ b/src/test/app/LoanBroker_test.cpp
@@ -1907,6 +1907,17 @@ class LoanBroker_test : public beast::unit_test::suite
             env(set(alice, vaultKL2.key), loanBrokerID(brokerKL.key), ter(tecNO_PERMISSION));
         }
 
+        // Pre-amendment: non-existent vault on update → tecNO_ENTRY
+        {
+            testcase("LoanBrokerSet pre-amendment: non-existent vault on update");
+            Env env(*this);
+            env.disableFeature(featureLendingProtocolV1_1);
+            auto const [vaultID, brokerKL] = setup(env);
+
+            // Update with a VaultID that doesn't exist
+            env(set(alice, uint256{1}), loanBrokerID(brokerKL.key), ter(tecNO_ENTRY));
+        }
+
         // Pre-amendment: Create without VaultID → temINVALID
         {
             testcase("LoanBrokerSet pre-amendment: create requires VaultID");