diff --git a/CMakeLists.txt b/CMakeLists.txt
index d868883..e4c5ecc 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -114,6 +114,8 @@ elseif(${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
   add_definitions(-DOS_MACOSX)
   set(CMAKE_MACOS_RPATH TRUE)
   set(CMAKE_INSTALL_NAME_DIR "${CMAKE_INSTALL_PREFIX}/lib")
+elseif(MSVC)
+  add_definitions(-D_CRT_SECURE_NO_WARNINGS)
 endif()
 
 if(BROTLI_EMSCRIPTEN)