diff --git a/options.h b/options.h
index 2113773..d6b64ea 100644
--- a/options.h
+++ b/options.h
@@ -6,6 +6,7 @@
 #ifndef __OPTIONS_H_ /* include guard */
 #define __OPTIONS_H_
 
+#include <sys/types.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>