diff --git a/ortools/base/random.cc b/ortools/base/random.cc
index d2d729b446..0212f0df05 100644
--- a/ortools/base/random.cc
+++ b/ortools/base/random.cc
@@ -19,6 +19,7 @@
 #endif
 #if defined(_MSC_VER)
 #include <windows.h>
+#include <Winsock2.h>
 #define PATH_MAX 4096
 #else
 #include <sys/time.h>