diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0d7bea58f..6e8623618 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -344,6 +344,7 @@ elseif(${CMAKE_CXX_COMPILER_ID} STREQUAL "MSVC")
   # using Visual Studio C++
   set(BOOST_COMPONENTS ${BOOST_COMPONENTS} zlib)
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /bigobj") # avoid compiler error C1128 from scripting_environment_lua.cpp
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /DWIN32_LEAN_AND_MEAN") # avoid compiler error C2011 from dual #include of winsock.h and winsock2.h
   add_dependency_defines(-DBOOST_LIB_DIAGNOSTIC)
   add_dependency_defines(-D_CRT_SECURE_NO_WARNINGS)
   add_dependency_defines(-DNOMINMAX) # avoid min and max macros that can break compilation