diff --git a/deploy/systemd/ci-backup-template.service b/deploy/systemd/ci-backup-template.service
index 460758a..7dbcc48 100644
--- a/deploy/systemd/ci-backup-template.service
+++ b/deploy/systemd/ci-backup-template.service
@@ -8,7 +8,11 @@ Type=oneshot
 User=root
 EnvironmentFile=/etc/ci/environment
 WorkingDirectory=/opt/ci/local-ci-cd-system
-ExecStart=/opt/ci/venv/bin/python -m ci_orchestrator template backup --all-templates
+# --keep-count 1: three generations of Windows templates cost ~195 GB and the
+# archives were byte-identical between runs (the templates rarely change), so
+# the extra generations bought nothing. --exclude WinBuildTest: retired test
+# template, ~26 GB per generation.
+ExecStart=/opt/ci/venv/bin/python -m ci_orchestrator template backup --all-templates --keep-count 1 --exclude WinBuildTest
 # Safety net: bring act-runner.service back up on any exit path (success,
 # failure, signal). The Python `finally` block can be skipped if the
 # service is killed mid-run, and a runner left stopped by a killed