diff --git a/src/monero_send_routine.cpp b/src/monero_send_routine.cpp
index c5dd2f7..b598756 100644
--- a/src/monero_send_routine.cpp
+++ b/src/monero_send_routine.cpp
@@ -343,7 +343,7 @@ void _reenterable_construct_and_send_tx(
 		step1_retVals,
 		constructionAttempt
 	] (
-		property_tree::ptree res
+		const property_tree::ptree &res
 	) -> void {
 		auto parsed_res = new__parsed_res__get_random_outs(res);
 		if (parsed_res.err_msg != none) {
@@ -405,7 +405,7 @@ void _reenterable_construct_and_send_tx(
 			step1_retVals,
 			step2_retVals
 		] (
-			property_tree::ptree res
+			const property_tree::ptree &res
 		) -> void {
 			// not actually expecting anything in a success response, so no need to parse
 			SendFunds_Success_RetVals success_retVals;
@@ -487,7 +487,7 @@ void monero_send_routine::async__send_funds(Async_SendFunds_Args args)
 		usable__sending_amount,
 		sec_viewKey, sec_spendKey, pub_spendKey
 	] (
-		property_tree::ptree res
+		const property_tree::ptree &res
 	) -> void {
 		auto parsed_res = new__parsed_res__get_unspent_outs(
 			res,
diff --git a/src/monero_send_routine.hpp b/src/monero_send_routine.hpp
index 5bb6ec5..0ee444c 100644
--- a/src/monero_send_routine.hpp
+++ b/src/monero_send_routine.hpp
@@ -56,7 +56,7 @@ namespace monero_send_routine
 	// Abstracted Send routine
 	// - Accessory types - Callbacks - Data fetch hooks
 	typedef std::function<void(
-		const property_tree::ptree // opted not to send str but already parsed structure - this may not be optimal but makes it so that e.g. emscr_async_bridge doesn't have to send the response as an escaped JSON string nor redundantly parse/stringify
+		const property_tree::ptree & // opted not to send str but already parsed structure - this may not be optimal but makes it so that e.g. emscr_async_bridge doesn't have to send the response as an escaped JSON string nor redundantly parse/stringify
 	)> api_fetch_cb_fn;
 	//
 	struct LightwalletAPI_Req_GetUnspentOuts