diff --git a/tests/slow/ExcludeIncludeStorageServers.toml b/tests/slow/ExcludeIncludeStorageServers.toml
index d195cf9a98..e209ad54be 100644
--- a/tests/slow/ExcludeIncludeStorageServers.toml
+++ b/tests/slow/ExcludeIncludeStorageServers.toml
@@ -1,3 +1,7 @@
+[configuration]
+# Keep one spare machine per datacenter so excluding a storage server cannot exhaust a replicated team.
+extraMachineCountDC = 1
+
 [[knobs]]
 dd_max_shards_on_large_teams=0