diff --git a/src/api/python/setup.py b/src/api/python/setup.py
index 063680e2b..9939f5962 100644
--- a/src/api/python/setup.py
+++ b/src/api/python/setup.py
@@ -16,7 +16,7 @@ from setuptools.command.bdist_egg import bdist_egg as _bdist_egg
 
 build_env = dict(os.environ)
 build_env['PYTHON'] = sys.executable
-build_env['CXXFLAGS'] = "-std=c++11"
+build_env['CXXFLAGS'] = build_env.get('CXXFLAGS', '') + " -std=c++11"
 
 ROOT_DIR = os.path.abspath(os.path.dirname(__file__))
 SRC_DIR_LOCAL = os.path.join(ROOT_DIR, 'core')