--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -141,7 +141,7 @@ ENDIF()
 IF(WANT_DEBUG)
 	SET(CMAKE_CXX_FLAGS "$ENV{CMAKE_CXX_FLAGS} -O0")
 ELSE()
-	SET(CMAKE_CXX_FLAGS "$ENV{CMAKE_CXX_FLAGS} -O3 -ffast-math")
+	SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
 ENDIF()
 
 IF(WANT_APPIMAGE)