diff --git a/source/clientserver/udaDefines.h b/source/clientserver/udaDefines.h
index ffcf615e..da26a1c2 100755
--- a/source/clientserver/udaDefines.h
+++ b/source/clientserver/udaDefines.h
@@ -128,6 +128,7 @@ extern "C" {
 
 #if defined(_WIN32)
 #  if !defined(__MINGW32__)
+#include <winsock2.h>
 LIBRARY_API int gettimeofday(struct timeval* tp, struct timezone* tzp);
 #  endif
 #endif