diff --git a/src/transactions/TransactionFrame.cpp b/src/transactions/TransactionFrame.cpp
index e86aad11b2..f898831b5a 100644
--- a/src/transactions/TransactionFrame.cpp
+++ b/src/transactions/TransactionFrame.cpp
@@ -236,7 +236,7 @@ TransactionFrame::getNumOperations() const
 Resource
 TransactionFrame::getResources(bool useByteLimitInClassic) const
 {
-    int64_t txSize = xdr::xdr_size(mEnvelope);
+    auto txSize = static_cast<int64_t>(this->getSize());
     if (isSoroban())
     {
         auto r = sorobanResources();
@@ -751,7 +751,7 @@ TransactionFrame::validateSorobanResources(SorobanNetworkConfig const& config,
             return false;
         }
     }
-    auto txSize = xdr::xdr_size(mEnvelope);
+    auto txSize = this->getSize();
     if (txSize > config.txMaxSizeBytes())
     {
         pushSimpleDiagnosticError(
@@ -1900,4 +1900,11 @@ TransactionFrame::getDiagnosticEvents() const
 {
     return mSorobanExtension->mDiagnosticEvents;
 }
+
+uint32_t
+TransactionFrame::getSize() const
+{
+    ZoneScoped;
+    return static_cast<uint32_t>(xdr::xdr_size(mEnvelope));
+}
 } // namespace stellar
diff --git a/src/transactions/TransactionFrame.h b/src/transactions/TransactionFrame.h
index cb331409eb..0b36d98cc2 100644
--- a/src/transactions/TransactionFrame.h
+++ b/src/transactions/TransactionFrame.h
@@ -47,6 +47,9 @@ using TransactionFramePtr = std::shared_ptr<TransactionFrame>;
 
 class TransactionFrame : public TransactionFrameBase
 {
+  private:
+    uint32_t getSize() const;
+
   protected:
     TransactionEnvelope mEnvelope;
     TransactionResult mResult;