diff --git a/compilers/GNU.CXX.cmake b/compilers/GNU.CXX.cmake
index 6d0ad14..f135452 100644
--- a/compilers/GNU.CXX.cmake
+++ b/compilers/GNU.CXX.cmake
@@ -1,7 +1,7 @@
 if(NOT DEFINED ENV{CXXFLAGS})
     if(CMAKE_CXX_COMPILER_ID MATCHES GNU)
         set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
-        set(CMAKE_CXX_FLAGS_RELEASE "-Ofast")
+        set(CMAKE_CXX_FLAGS_RELEASE "-O3")
         set(CMAKE_CXX_FLAGS_DEBUG "-O0 -g")
     endif()
 endif()