diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2360aed0fc6a663bd4c364beb847a3a8c84c7f30..de1367a97064c0cddfc13aa345d43b1f49085da2 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -520,6 +520,7 @@ if(MSVC)
   add_definitions(-D_USE_MATH_DEFINES -DNOMINMAX 
                   -D_CRT_SECURE_NO_DEPRECATE -D_SCL_SECURE_NO_DEPRECATE)
   set(GMSH_SRC ${GMSH_SRC};Fltk/Win32Icon.rc)
+  list(APPEND EXTERNAL_LIBRARIES "ws2_32")
 endif(MSVC)
 
 list(SORT CONFIG_OPTIONS)