diff --git a/gnes/composer/flask.py b/gnes/composer/flask.py
index 5b05dcf4..f5553693 100644
--- a/gnes/composer/flask.py
+++ b/gnes/composer/flask.py
@@ -14,8 +14,6 @@
 #  limitations under the License.
 import io
 
-import copy
-
 from .base import YamlComposer
 from ..cli.parser import set_composer_parser
 from ..helper import set_logger