diff --git a/include/spdlog/common-inl.h b/include/spdlog/common-inl.h
index c3e99222..5fa4e5d9 100644
--- a/include/spdlog/common-inl.h
+++ b/include/spdlog/common-inl.h
@@ -56,7 +56,7 @@ SPDLOG_INLINE spdlog_ex::spdlog_ex(std::string msg)
 SPDLOG_INLINE spdlog_ex::spdlog_ex(const std::string &msg, int last_errno)
 {
     memory_buf_t outbuf;
-    fmt::format_system_error(outbuf, last_errno, msg);
+    fmt::format_system_error(outbuf, last_errno, msg.c_str());
     msg_ = fmt::to_string(outbuf);
 }