diff --git a/cmake/compilerFlags.cmake b/cmake/compilerFlags.cmake
index 1c5ffab2..190b1c67 100644
--- a/cmake/compilerFlags.cmake
+++ b/cmake/compilerFlags.cmake
@@ -38,7 +38,7 @@ if ( MINGW OR UNIX OR MSYS ) # MINGW, Linux, APPLE, CYGWIN
 
         add_compile_options(-Wp,-D_GLIBCXX_ASSERTIONS)
 
-        if (CMAKE_BUILD_TYPE STREQUAL Release AND NOT APPLE)
+        if (CMAKE_BUILD_TYPE STREQUAL Release AND NOT APPLE AND NOT MSYS)
             add_compile_options(-Wp,-D_FORTIFY_SOURCE=2) # Requires to compile with -O2
         endif()