diff --git a/requirements_ref.txt b/requirements_ref.txt
index cff1fd8..b2d1f8a 100644
--- a/requirements_ref.txt
+++ b/requirements_ref.txt
@@ -25,7 +25,7 @@ inflection==0.4.0         # via connexion
 itsdangerous==1.1.0       # via flask
 jinja2==2.11.2            # via flask, swagger-ui-bundle
 jsonschema==3.2.0         # via connexion, openapi-spec-validator
-mako==1.1.2               # via alembic
+mako==1.2.2               # via alembic
 markupsafe==1.1.1         # via jinja2, mako
 openapi-spec-validator==0.2.8  # via connexion
 pip-tools==5.1.0          # via -r etc/requirements.in