diff --git a/include/gmssl/socket.h b/include/gmssl/socket.h
index 926d22b7..80437453 100644
--- a/include/gmssl/socket.h
+++ b/include/gmssl/socket.h
@@ -45,6 +45,7 @@ typedef int tls_socklen_t;
 #include <arpa/inet.h>
 #include <sys/types.h>
 #include <sys/socket.h>
+#include <sys/select.h>
 #include <netinet/in.h>
 #include <unistd.h>