diff --git a/Dockerfile b/Dockerfile
index c9d9e3c..64a2c36 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,9 +1,12 @@
-FROM python:3-buster
+FROM python:3.9-slim-bullseye
 
-RUN apt-get update && apt-get install -y apt-transport-https ca-certificates curl gnupg2 software-properties-common && \
-    curl -fsSL https://download.docker.com/linux/debian/gpg | apt-key add - && \
-    add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/debian $(lsb_release -cs) stable" && \
-    apt-get update && apt-get install -y docker-ce-cli
+RUN apt-get update && apt-get install -y --no-install-recommends git ca-certificates curl gnupg lsb-release && \
+    install -m 0755 -d /etc/apt/keyrings && \
+    curl -fsSL https://download.docker.com/linux/debian/gpg | gpg --dearmor -o /etc/apt/keyrings/docker.gpg && \
+    chmod a+r /etc/apt/keyrings/docker.gpg && \
+    echo "deb [arch=amd64 signed-by=/etc/apt/keyrings/docker.gpg] https://download.docker.com/linux/debian bullseye stable" > /etc/apt/sources.list.d/docker.list && \
+    apt-get update && apt-get install -y --no-install-recommends docker-ce-cli && \
+    rm -rf /var/lib/apt/lists/*
 
 ADD requirements.txt /
 RUN pip3 install -r /requirements.txt && mkdir /code