diff --git a/src/psbt.h b/src/psbt.h
index b636f0348b7..fc9ac71eee9 100644
--- a/src/psbt.h
+++ b/src/psbt.h
@@ -178,7 +178,7 @@ void SerializeHDKeypath(Stream& s, KeyOriginInfo hd_keypath)
 template<typename Stream>
 void SerializeHDKeypaths(Stream& s, const std::map<CPubKey, KeyOriginInfo>& hd_keypaths, CompactSizeWriter type)
 {
-    for (auto keypath_pair : hd_keypaths) {
+    for (const auto& keypath_pair : hd_keypaths) {
         if (!keypath_pair.first.IsValid()) {
             throw std::ios_base::failure("Invalid CPubKey being serialized");
         }