diff --git a/src/sflow_plugin/sflow_collector.cpp b/src/sflow_plugin/sflow_collector.cpp
index 3f8ea7c..400f5a9 100644
--- a/src/sflow_plugin/sflow_collector.cpp
+++ b/src/sflow_plugin/sflow_collector.cpp
@@ -9,6 +9,7 @@
 #ifdef _WIN32
 #include <winsock2.h>
 #include <ws2ipdef.h> // sockaddr_in6
+#include <ws2tcpip.h> // socklen_t
 #else
 #include <arpa/inet.h>
 #include <netinet/in.h>