diff --git a/ref-test/requirements.txt b/ref-test/requirements.txt
index 7b818ef..898dd2d 100644
--- a/ref-test/requirements.txt
+++ b/ref-test/requirements.txt
@@ -18,6 +18,7 @@ itsdangerous==2.1.2
 Jinja2==3.1.2
 MarkupSafe==2.1.1
 pycparser==2.21
+PyMySQL==1.0.2
 python-dotenv==0.20.0
 six==1.16.0
 SQLAlchemy==1.4.40