diff --git a/.changeset/three-cooks-check.md b/.changeset/three-cooks-check.md
new file mode 100644
index 0000000000000..e84ba9d3c3ecf
--- /dev/null
+++ b/.changeset/three-cooks-check.md
@@ -0,0 +1,5 @@
+---
+'@eth-optimism/ci-builder': patch
+---
+
+Upgrade to Debian 11
diff --git a/ops/docker/ci-builder/Dockerfile b/ops/docker/ci-builder/Dockerfile
index ede2285581367..f2bec8f43fefa 100644
--- a/ops/docker/ci-builder/Dockerfile
+++ b/ops/docker/ci-builder/Dockerfile
@@ -2,7 +2,7 @@ FROM ethereum/client-go:alltools-v1.10.17 as geth
 
 FROM ethereumoptimism/foundry:latest as foundry
 
-FROM python:3.8.12-slim-buster
+FROM python:3.8.13-slim-bullseye
 
 ENV GOPATH /go
 ENV PATH /usr/local/go/bin:$GOPATH/bin:$PATH