diff --git a/lib/timeval.h b/lib/timeval.h
index fe99e2896..c5ff9a8cb 100644
--- a/lib/timeval.h
+++ b/lib/timeval.h
@@ -42,6 +42,7 @@
 
 #if defined(WIN32) && !defined(__GNUC__) || defined(__MINGW32__)
 #include <time.h>
+#include <winsock.h>
 #else
 #include <sys/time.h>
 #endif