diff --git a/include/xrpl/protocol/detail/ledger_entries.macro b/include/xrpl/protocol/detail/ledger_entries.macro
index b7333b2f0c..0a9d86c287 100644
--- a/include/xrpl/protocol/detail/ledger_entries.macro
+++ b/include/xrpl/protocol/detail/ledger_entries.macro
@@ -616,7 +616,7 @@ LEDGER_ENTRY(ltSPONSORSHIP, 0x0090, Sponsorship, sponsorship, ({
     {sfPreviousTxnLgrSeq,    soeREQUIRED},
     {sfOwner,                soeREQUIRED},
     {sfSponsee,              soeREQUIRED},
-    {sfFeeAmount,            soeDEFAULT},
+    {sfFeeAmount,            soeOPTIONAL},
     {sfMaxFee,               soeOPTIONAL},
     {sfReserveCount,         soeDEFAULT},
     {sfOwnerNode,            soeREQUIRED},
diff --git a/src/xrpld/app/tx/detail/Transactor.cpp b/src/xrpld/app/tx/detail/Transactor.cpp
index 018c0f9416..5ec1c2ac2f 100644
--- a/src/xrpld/app/tx/detail/Transactor.cpp
+++ b/src/xrpld/app/tx/detail/Transactor.cpp
@@ -478,9 +478,7 @@ Transactor::payFee()
     auto const feeAmountAfter = sle->getFieldAmount(payer.balanceField) - feePaid;
 
     if (feeAmountAfter == beast::zero && payer.balanceField == sfFeeAmount)
-        // Because ltSponsorship.sfFeeAmount is soeDEFAULT
-        // TODO: Use whether the field is soeDEFAULT instead of sfFeeAmount in
-        // the condition.
+        // Because ltSponsorship.sfFeeAmount is soeOptional
         sle->makeFieldAbsent(payer.balanceField);
     else
         sle->setFieldAmount(payer.balanceField, feeAmountAfter);