diff --git a/support/debian.Dockerfile b/support/debian.Dockerfile
index 4d61be5d58b..370fe659509 100644
--- a/support/debian.Dockerfile
+++ b/support/debian.Dockerfile
@@ -82,8 +82,32 @@ RUN ./aws/install
 FROM garden-base as garden-gcloud-base
 ENV GCLOUD_VERSION=478.0.0
 ENV GCLOUD_SHA256="225c3a1f9b47241467a4ad8da0f432a57bade10c8d44158920003ae698f6d195"
+ENV PYTHON_VERSION=3.11.9
+
+# Upgrade Python to 3.11.
+# The default python3 in Debian 10 (buster) is too old.
+RUN apt-get install \
+    build-essential \
+    libncursesw5-dev \
+    libssl-dev \
+    libsqlite3-dev \
+    tk-dev \
+    libgdbm-dev \
+    libc6-dev \
+    libbz2-dev \
+    libffi-dev \
+    zlib1g-dev
+
+RUN wget https://www.python.org/ftp/python/${PYTHON_VERSION}/Python-${PYTHON_VERSION}.tgz
+
+RUN tar xzf Python-${PYTHON_VERSION}.tgz && \
+    cd Python-${PYTHON_VERSION} && \
+    ./configure --enable-optimizations && \
+    make -j 2 && \
+    make altinstall
 
-RUN curl -O https://dl.google.com/dl/cloudsdk/channels/rapid/downloads/google-cloud-cli-${GCLOUD_VERSION}-linux-x86_64.tar.gz
+# Install Google Cloud CLI.
+RUN wget https://dl.google.com/dl/cloudsdk/channels/rapid/downloads/google-cloud-cli-${GCLOUD_VERSION}-linux-x86_64.tar.gz
 RUN echo "${GCLOUD_SHA256}  google-cloud-cli-${GCLOUD_VERSION}-linux-x86_64.tar.gz" | sha256sum -c
 RUN tar -xf google-cloud-cli-${GCLOUD_VERSION}-linux-x86_64.tar.gz
 RUN ./google-cloud-sdk/install.sh --quiet