diff --git a/src/common/input/InputDevice.cpp b/src/common/input/InputDevice.cpp
index aa63b6dc7..e333cc7d4 100644
--- a/src/common/input/InputDevice.cpp
+++ b/src/common/input/InputDevice.cpp
@@ -109,7 +109,7 @@ std::string PortUserFormat(std::string_view port)
 void PortStr2Int(std::string_view port, int *port_num, int *slot)
 {
 	*slot = PORT_INVALID;
-	auto &ret = std::from_chars(port.data(), port.data() + port.size(), *port_num);
+	auto ret = std::from_chars(port.data(), port.data() + port.size(), *port_num);
 	assert(ret.ec != std::errc::invalid_argument);
 	if (ret.ptr != port.data() + port.size()) {
 		++ret.ptr;