diff --git a/include/spdlog/details/tcp_client_unix.h b/include/spdlog/details/tcp_client_unix.h
index 9364eda5..945ef2df 100644
--- a/include/spdlog/details/tcp_client_unix.h
+++ b/include/spdlog/details/tcp_client_unix.h
@@ -61,9 +61,9 @@ public:
         int last_errno = 0;
         for (auto *rp = addrinfo_result; rp != nullptr; rp = rp->ai_next) {
 #if defined(SOCK_CLOEXEC)
-            const int flags = SOCK_CLOEXEC;
+            constexpr int flags = SOCK_CLOEXEC;
 #else
-            const int flags = 0;
+            constexpr int flags = 0;
 #endif
             socket_ = ::socket(rp->ai_family, rp->ai_socktype | flags, rp->ai_protocol);
             if (socket_ == -1) {