diff --git a/tools/docker/build.sh b/tools/docker/build.sh
index e3ff5707a..e9453c439 100755
--- a/tools/docker/build.sh
+++ b/tools/docker/build.sh
@@ -12,6 +12,11 @@ IFS=$'\n\t'
 #   given value is only the base of the tag because the things like the CPU
 #   architecture are also added to the full tag.
 
+# Docker BuildKit is the default builder starting with Docker Engine 23.0. See
+# https://docs.docker.com/engine/release-notes/23.0/#new. Until we've done the
+# work tracked by https://github.com/certbot/certbot/issues/9587, let's
+# continue using the legacy builder.
+export DOCKER_BUILDKIT=0
 WORK_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
 REPO_ROOT="$(dirname "$(dirname "${WORK_DIR}")")"
 source "$WORK_DIR/lib/common"