diff --git a/.gitignore b/.gitignore
index 8465bde..047ccb5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -9,3 +9,6 @@
 
 # go
 /vendor/
+
+# Python bytecode written by configs/test_felhom_os_apply.py
+configs/__pycache__/
diff --git a/cmd/felhom-agent/main.go b/cmd/felhom-agent/main.go
index 7140f02..29dca44 100644
--- a/cmd/felhom-agent/main.go
+++ b/cmd/felhom-agent/main.go
@@ -3496,8 +3496,12 @@ func (f *selftestFlag) Set(v string) error {
 		f.mode = "identity-consume"
 	case "controller-swap":
 		f.mode = "controller-swap"
+	case "os-update":
+		f.mode = "os-update"
+	case "wgtunnel": // dispatched since S3 but refused here until 2026-10-04 (TestSelftestFlag_AcceptsEveryDispatchedMode)
+		f.mode = "wgtunnel"
 	default:
-		return fmt.Errorf("invalid --selftest value %q (want read|task|hub|storage|backup|restore-test|restore-test-due|pbs-verify|bring-up|provision|escrow-create|escrow-consume|identity-consume|controller-swap)", v)
+		return fmt.Errorf("invalid --selftest value %q (want read|task|hub|storage|backup|restore-test|restore-test-due|pbs-verify|lanresolver|wgtunnel|bring-up|provision|escrow-create|escrow-consume|identity-consume|controller-swap|os-update)", v)
 	}
 	return nil
 }
diff --git a/cmd/felhom-agent/selftest_flag_test.go b/cmd/felhom-agent/selftest_flag_test.go
new file mode 100644
index 0000000..4386c43
--- /dev/null
+++ b/cmd/felhom-agent/selftest_flag_test.go
@@ -0,0 +1,39 @@
+package main
+
+import (
+	"os"
+	"regexp"
+	"strings"
+	"testing"
+)
+
+// Every mode the dispatcher (`switch selftest.mode`) runs must be ACCEPTED by the --selftest flag. Found live
+// 2026-10-04: --selftest=os-update had a dispatch case and a function but the flag's allow-list refused it, so the
+// debug action could not run. Red-proof: drop the "os-update" case from selftestFlag.Set and this fails.
+func TestSelftestFlag_AcceptsEveryDispatchedMode(t *testing.T) {
+	src, err := os.ReadFile("main.go")
+	if err != nil {
+		t.Fatal(err)
+	}
+	s := string(src)
+	i := strings.Index(s, "switch selftest.mode {")
+	if i < 0 {
+		t.Fatal("dispatch switch not found")
+	}
+	block := s[i:]
+	block = block[:strings.Index(block, "\n\t}\n")]
+	modes := regexp.MustCompile(`(?m)^\tcase "([a-z-]+)":`).FindAllStringSubmatch(block, -1)
+	if len(modes) < 5 {
+		t.Fatalf("parsed only %d dispatch cases — the parser is wrong", len(modes))
+	}
+	var bad []string
+	for _, m := range modes {
+		var f selftestFlag
+		if err := f.Set(m[1]); err != nil {
+			bad = append(bad, m[1])
+		}
+	}
+	if len(bad) > 0 {
+		t.Fatalf("dispatched but refused by --selftest: %v", bad)
+	}
+}