diff --git a/src/osgPlugins/osc/CMakeLists.txt b/src/osgPlugins/osc/CMakeLists.txt
index 135f98642..af9d2e49d 100755
--- a/src/osgPlugins/osc/CMakeLists.txt
+++ b/src/osgPlugins/osc/CMakeLists.txt
@@ -30,6 +30,7 @@ SET(TARGET_H
 )
 
 if(WIN32)
+    SET(TARGET_EXTERNAL_LIBRARIES ws2_32)
     SET(TARGET_SRC
         ${TARGET_SRC}
         ip/win32/NetworkingUtils.cpp