diff --git a/include/curl/multi.h b/include/curl/multi.h
index 1d3b123a2..ac114be4d 100644
--- a/include/curl/multi.h
+++ b/include/curl/multi.h
@@ -51,6 +51,7 @@
 #else
 #include <sys/socket.h>
 #include <sys/time.h>
+#include <sys/types.h>
 #endif
 
 #include "curl.h"