diff --git a/cdn.tf b/cdn.tf
index 349486e..df30273 100644
--- a/cdn.tf
+++ b/cdn.tf
@@ -89,9 +89,19 @@ resource "bunnynet_compute_script" "rpkgs_router" {
 # slot that is not listed here would hide every package the per-minor index does
 # not carry, so this stays empty until a slot has been backfilled.
 resource "bunnynet_compute_script_variable" "rpkgs_router_union_slots" {
-  script        = bunnynet_compute_script.rpkgs_router.id
-  name          = "UNION_SLOTS"
-  default_value = ""
+  script = bunnynet_compute_script.rpkgs_router.id
+  name   = "UNION_SLOTS"
+  # Enabled. Until this was set, every client resolved against the generic
+  # index and never reached a per-minor binary: an R 4.6.1 client on resolute
+  # downloaded the 4.5-built rlang (2079570 bytes) while the correct 4.6 build
+  # (2075106 bytes) sat unused one directory away, and died at load with
+  # `undefined symbol: SETLENGTH`.
+  #
+  # Verified before enabling, against the staging zone with the same script and
+  # the same origin: all 16 slots report zero regressions against the generic
+  # slot, an excluded R minor is sent to CRAN, a client without an R minor
+  # still gets the generic index, and tarball requests are never rewritten.
+  default_value = join(",", local.rpkgs_slots)
   required      = false
 }