diff --git a/include/sys/select.h b/include/sys/select.h
index 54d8030ff485cd6dfe854f4ce8953fbc65cf07df..7cb0af43de44a036d1b6e057a4e0827a37ecc18c 100644
--- a/include/sys/select.h
+++ b/include/sys/select.h
@@ -15,6 +15,8 @@ extern "C" {
 
 #define FD_SETSIZE 1024
 
+typedef unsigned long fd_mask;
+
 typedef struct
 {
 	unsigned long fds_bits[FD_SETSIZE / 8 / sizeof(long)];