diff --git a/clib/tcpnet.h b/clib/tcpnet.h
index f153d27..49da59c 100644
--- a/clib/tcpnet.h
+++ b/clib/tcpnet.h
@@ -17,7 +17,7 @@ public:
 	[[nodiscard]] std::vector<std::string> client(const std::string &address, int portno, const std::vector<std::string> &requests) const;
 
 private:
-	static const bool USE_LENGTH_HEADER = true;
+	static constexpr bool USE_LENGTH_HEADER = true;
 	static std::string read_from_socket(int sockfd) ;
 	static void write_to_socket(int sockfd, const std::string &str) ;
 };