diff --git a/include/spdlog/details/log_msg.h b/include/spdlog/details/log_msg.h
index 39c054f5..e575597d 100644
--- a/include/spdlog/details/log_msg.h
+++ b/include/spdlog/details/log_msg.h
@@ -13,14 +13,14 @@ namespace details {
 struct SPDLOG_API log_msg {
     log_msg() = default;
     log_msg(log_clock::time_point log_time,
-            source_loc loc,
+            const source_loc &loc,
             string_view_t logger_name,
             level lvl,
             string_view_t msg,
             log_attributes attributes);
     log_msg(log_clock::time_point log_time, const source_loc &loc, string_view_t logger_name, level lvl, string_view_t msg);
     log_msg(const source_loc &loc, string_view_t logger_name, level lvl, string_view_t msg);
-    log_msg(source_loc loc, string_view_t logger_name, level lvl, string_view_t msg, log_attributes attributes);
+    log_msg(const source_loc &loc, string_view_t logger_name, level lvl, string_view_t msg, log_attributes attributes);
     log_msg(string_view_t logger_name, level lvl, string_view_t msg, log_attributes attributes);
     log_msg(string_view_t logger_name, level lvl, string_view_t msg);
     log_msg(const log_msg &other) = default;
diff --git a/src/details/log_msg.cpp b/src/details/log_msg.cpp
index 73897a9c..d2231aa7 100644
--- a/src/details/log_msg.cpp
+++ b/src/details/log_msg.cpp
@@ -8,32 +8,13 @@
 namespace spdlog {
 namespace details {
 
-log_msg::log_msg(spdlog::log_clock::time_point log_time,
-                 spdlog::source_loc loc,
-                 string_view_t a_logger_name,
-                 spdlog::level lvl,
-                 spdlog::string_view_t msg,
-                 spdlog::log_attributes attributes)
-    : logger_name(a_logger_name),
-      log_level(lvl),
-      time(log_time)
-#ifndef SPDLOG_NO_THREAD_ID
-      ,
-      thread_id(os::thread_id())
-#endif
-      ,
-      source(loc),
-      payload(msg),
-      attributes(attributes) {
-}
-
 log_msg::log_msg(const log_clock::time_point log_time,
-                 const source_loc loc,
-                 const string_view_t a_logger_name,
+                 const source_loc &loc,
+                 const string_view_t logger_name,
                  const level lvl,
                  const string_view_t msg,
                  const log_attributes attributes)
-    : logger_name(a_logger_name),
+    : logger_name(logger_name),
       log_level(lvl),
       time(log_time),
 #ifdef SPDLOG_NO_THREAD_ID
@@ -64,20 +45,16 @@ log_msg::log_msg(const log_clock::time_point log_time,
 }
 
 log_msg::log_msg(const source_loc &loc, const string_view_t logger_name, const level lvl, const string_view_t msg)
-    : log_msg(os::now(), loc, logger_name, lvl, msg) {}
+    : log_msg(os::now(), loc, logger_name, lvl, msg, {}) {}
 
-log_msg::log_msg(spdlog::source_loc loc,
-                 string_view_t a_logger_name,
-                 spdlog::level lvl,
-                 spdlog::string_view_t msg,
-                 spdlog::log_attributes attributes)
-    : log_msg(os::now(), loc, a_logger_name, lvl, msg, attributes) {}
+log_msg::log_msg(const source_loc &loc, string_view_t logger_name, level lvl, string_view_t msg, log_attributes attributes)
+    : log_msg(os::now(), loc, logger_name, lvl, msg, attributes) {}
 
 log_msg::log_msg(const string_view_t logger_name, const level lvl, const string_view_t msg)
     : log_msg(os::now(), source_loc{}, logger_name, lvl, msg) {}
 
-log_msg::log_msg(string_view_t a_logger_name, spdlog::level lvl, spdlog::string_view_t msg, spdlog::log_attributes attributes)
-    : log_msg(os::now(), source_loc{}, a_logger_name, lvl, msg, attributes) {}
+log_msg::log_msg(const string_view_t logger_name, const level lvl, const string_view_t msg, const log_attributes attributes)
+    : log_msg(os::now(), source_loc{}, logger_name, lvl, msg, attributes) {}
 
 }  // namespace details
 }  // namespace spdlog
diff --git a/tests/test_attributes.cpp b/tests/test_attributes.cpp
index 7907abb2..b4882057 100644
--- a/tests/test_attributes.cpp
+++ b/tests/test_attributes.cpp
@@ -1,7 +1,6 @@
 #include <future>
 
 #include "includes.h"
-#include "spdlog/mdc.h"
 #include "spdlog/sinks/stdout_sinks.h"
 #include "spdlog/spdlog.h"
 #include "test_sink.h"
@@ -182,7 +181,7 @@ TEST_CASE("attribute test - multi threaded") {
     // put attributes with multiple threads simultaneously
     std::vector<std::future<void>> tasks;
     for (unsigned int i = 0; i < n_tasks; ++i) {
-        auto task = std::async([&logger, i] {
+        auto task = std::async([&logger, i, n_values] {
             for (auto j = 0; j < n_values; ++j)
                 logger.attrs().put(fmt_lib::format("log_{}_key_{}", i, j), fmt_lib::format("log_{}_value_{}", i, j));
         });