diff --git a/scripts/deployment/complete-config-ready-chains.sh b/scripts/deployment/complete-config-ready-chains.sh
index 8099ece..b471da0 100755
--- a/scripts/deployment/complete-config-ready-chains.sh
+++ b/scripts/deployment/complete-config-ready-chains.sh
@@ -71,6 +71,10 @@ if ! require_private_key_env; then
   exit 1
 fi
 
+# Custom CCIPRouter on Chain 138 (smom-dbis-138/contracts/ccip/CCIPRouter.sol) maintains an allowlist.
+# If a selector is missing, bridge.calculateFee / ccipSend revert with CCIPRouter: chain not supported.
+CCIP_ROUTER="${CCIP_ROUTER:-}"
+
 run_or_echo() {
   if [[ "$DRY_RUN" = "1" ]]; then
     echo "  [DRY RUN] $*"
@@ -87,6 +91,21 @@ run_or_echo() {
   fi
 }
 
+ensure_router_supports_selector() {
+  local label="$1"
+  local selector="$2"
+  [[ -z "$CCIP_ROUTER" || -z "$selector" ]] && return 0
+  local rout="${CCIP_ROUTER,,}"
+  local supported
+  supported=$(cast call "$rout" "supportedChains(uint64)(bool)" "$selector" --rpc-url "$CHAIN138_RPC" 2>/dev/null || echo "false")
+  if [[ "$supported" != "true" ]]; then
+    echo "  CCIP router: enabling chain selector for $label ($selector)..."
+    run_or_echo "cast send $rout \"addSupportedChain(uint64)\" $selector --rpc-url $CHAIN138_RPC --private-key \$PRIVATE_KEY --legacy --gas-limit 250000 --gas-price 2000000000"
+  else
+    echo "  CCIP router: $label selector already supported ($selector)"
+  fi
+}
+
 configure_chain_138_destination() {
   local label="$1"
   local selector="$2"
@@ -127,6 +146,18 @@ configure_remote_chain_destination() {
   fi
 }
 
+# ---- Step 0: CCIPRouter allowlist (must precede bridge fee quotes / sends) ----
+echo ""
+echo "Step 0: CCIP router on Chain 138 → allowlist selectors (Gnosis, Cronos, Celo, Wemix)"
+if [[ -n "$CCIP_ROUTER" ]]; then
+  ensure_router_supports_selector "Gnosis" "$GNOSIS_SELECTOR"
+  ensure_router_supports_selector "Cronos" "$CRONOS_SELECTOR"
+  ensure_router_supports_selector "Celo" "$CELO_SELECTOR"
+  ensure_router_supports_selector "Wemix" "$WEMIX_SELECTOR"
+else
+  echo "  Skip (CCIP_ROUTER not set in .env)"
+fi
+
 # ---- Step A: On Chain 138, add Gnosis/Cronos/Celo/Wemix as destinations ----
 echo ""
 echo "Step A: Chain 138 bridges → add Gnosis, Cronos, Celo, Wemix as destinations"