diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5a1333397f..919cfcd243 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -82,12 +82,15 @@ if(WIN32)
   set(CURL_TARGET_WINDOWS_VERSION "" CACHE STRING "Minimum target Windows version as hex string")
   if(CURL_TARGET_WINDOWS_VERSION)
     add_definitions(-D_WIN32_WINNT=${CURL_TARGET_WINDOWS_VERSION})
+    set(CMAKE_REQUIRED_DEFINITIONS "${CMAKE_REQUIRED_DEFINITIONS} -D_WIN32_WINNT=${CURL_TARGET_WINDOWS_VERSION}")
   elseif(ENABLE_INET_PTON)
     # _WIN32_WINNT_VISTA (0x0600)
     add_definitions(-D_WIN32_WINNT=0x0600)
+    set(CMAKE_REQUIRED_DEFINITIONS "${CMAKE_REQUIRED_DEFINITIONS} -D_WIN32_WINNT=0x0600")
   else()
     # _WIN32_WINNT_WINXP (0x0501)
     add_definitions(-D_WIN32_WINNT=0x0501)
+    set(CMAKE_REQUIRED_DEFINITIONS "${CMAKE_REQUIRED_DEFINITIONS} -D_WIN32_WINNT=0x0501")
   endif()
 endif()
 option(CURL_LTO "Turn on compiler Link Time Optimizations" OFF)