diff --git a/Dockerfile b/Dockerfile
index 82bddd9..2a9a7d5 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,6 +1,6 @@
 # Use the official lightweight Python image.
 # https://hub.docker.com/_/python
-FROM python:3.7-slim
+FROM python:3.9.6-slim
 
 # Copy local code to the container image.
 ENV APP_HOME /app