diff --git a/src/wallet/spend.cpp b/src/wallet/spend.cpp
index bffb665fa85..001acd04e20 100644
--- a/src/wallet/spend.cpp
+++ b/src/wallet/spend.cpp
@@ -569,8 +569,12 @@ std::optional<SelectionResult> SelectCoins(const CWallet& wallet, CoinsResult& a
             if (!coin_control.GetExternalOutput(outpoint, txout)) {
                 return std::nullopt;
             }
+        }
+
+        if (input_bytes == -1) {
             input_bytes = CalculateMaximumSignedInputSize(txout, outpoint, &coin_control.m_external_provider, &coin_control);
         }
+
         // If available, override calculated size with coin control specified size
         if (coin_control.HasInputWeight(outpoint)) {
             input_bytes = GetVirtualTransactionSize(coin_control.GetInputWeight(outpoint), 0, 0);