diff --git a/cmake/compilerFlags.cmake b/cmake/compilerFlags.cmake
index b4c8d3dc77..e17199edd2 100644
--- a/cmake/compilerFlags.cmake
+++ b/cmake/compilerFlags.cmake
@@ -5,7 +5,9 @@ if (NOT CMAKE_CXX_STANDARD)
   set(CMAKE_CXX_STANDARD 17)
 endif()
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
-set(CMAKE_CXX_EXTENSIONS ON)
+if (CYGWIN) # Cygwin and MSYS
+  set(CMAKE_CXX_EXTENSIONS ON)
+endif()
 
 if ( MINGW OR UNIX OR MSYS ) # MINGW, Linux, APPLE, CYGWIN
     if (${CMAKE_CXX_COMPILER_ID} STREQUAL GNU)