diff --git a/CMakeLists.txt b/CMakeLists.txt
index c4ee9a9b99..beafd911a0 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -148,9 +148,9 @@ endif(MSVC)
 # a newer version of the C library, i.e. Visual Studio 2015 or
 # later, as it depends on C99 features introduced in VS 2015.
 #
-#if(MINGW)
-#    add_definitions(-D_WIN32_WINNT=0x0600)
-#endif(MINGW)
+if(MINGW)
+    add_definitions(-D_WIN32_WINNT=0x0600)
+endif(MINGW)
 
 #
 # Build all runtimes in the top-level binary directory; that way,