diff --git a/cert.db b/cert.db
index f6290128..5736575c 100644
Binary files a/cert.db and b/cert.db differ
diff --git a/certdata/epki_cross_sign_test.go b/certdata/epki_cross_sign_test.go
new file mode 100644
index 00000000..9ec0bd07
--- /dev/null
+++ b/certdata/epki_cross_sign_test.go
@@ -0,0 +1,48 @@
+package main
+
+import (
+	"bytes"
+	"crypto/x509"
+	"slices"
+	"testing"
+)
+
+// Cross-signs must provide paths to the older root without allowing issuer
+// selection to cycle between the older root and G2.
+func TestEPKICrossSignsDoNotFormLoop(t *testing.T) {
+	var older, g2 *x509.Certificate
+	for _, cert := range loadBundle(t, caBundleFile) {
+		// Trust anchors do not depend on their historical self-signature algorithm.
+		if !cert.IsCA || !bytes.Equal(cert.RawSubject, cert.RawIssuer) {
+			continue
+		}
+		if slices.Contains(cert.Subject.OrganizationalUnit, "ePKI Root Certification Authority") {
+			older = cert
+		}
+		if cert.Subject.CommonName == "ePKI Root Certification Authority - G2" {
+			g2 = cert
+		}
+	}
+	if older == nil || g2 == nil {
+		t.Fatal("both self-signed ePKI roots must remain in the root bundle")
+	}
+
+	reverseCrossSigns := 0
+	for _, cert := range loadBundle(t, intBundleFile) {
+		if bytes.Equal(cert.RawSubject, older.RawSubject) && bytes.Equal(cert.RawIssuer, g2.RawSubject) {
+			t.Errorf("older ePKI root issued by G2 can form a loop (serial %X)", cert.SerialNumber)
+		}
+		if bytes.Equal(cert.RawSubject, g2.RawSubject) && bytes.Equal(cert.RawIssuer, older.RawSubject) {
+			if !bytes.Equal(cert.RawSubjectPublicKeyInfo, g2.RawSubjectPublicKeyInfo) {
+				t.Error("ePKI G2 cross-sign does not share the retained G2 root's key")
+			}
+			if err := cert.CheckSignatureFrom(older); err != nil {
+				t.Errorf("ePKI G2 cross-sign cannot terminate at the older root: %v", err)
+			}
+			reverseCrossSigns++
+		}
+	}
+	if reverseCrossSigns == 0 {
+		t.Error("missing ePKI G2 cross-signs supporting clients that trust only the older root")
+	}
+}
diff --git a/certdata/int-bundle.txt b/certdata/int-bundle.txt
index 4c1e9e9c..8f35fa94 100644
--- a/certdata/int-bundle.txt
+++ b/certdata/int-bundle.txt
@@ -3505,46 +3505,6 @@ Details:
 	OCSP server:
 		- http://uniper-group-ca-2-2015.ocsp.d-trust.net
 CERTIFICATE
-Subject: /C=TW/O=Chunghwa Telecom Co., Ltd./OU=ePKI Root Certification
-    Authority
-Issuer: /ePKI Root Certification Authority - G2/C=TW/O=Chunghwa Telecom Co.,
-    Ltd.
-	Signature algorithm: RSA / SHA256
-Details:
-	Public key: RSA-4096
-	Serial number: 7083007561045021846628119216699988972
-	AKI: 72:5B:BA:AA:72:38:EE:25:90:24:B5:94:22:FA:09:88:CA:8B:0A:FB
-	SKI: 1E:0C:F7:B6:67:F2:E1:92:26:09:45:C0:55:39:2E:77:3F:42:4A:A2
-	Valid from: 2015-11-17T08:31:41+0000
-	     until: 2034-12-20T02:31:27+0000
-	Key usages: cert sign, crl sign
-	Basic constraints: valid, is a CA certificate
-	SANs (0):
-	1 AIA:
-		http://eca.hinet.net/repository/Certs/IssuedToThisCA.p7b
-	OCSP server:
-		- http://ocsp.eca.hinet.net/OCSP/ocspG2sha2
-CERTIFICATE
-Subject: /C=TW/O=Chunghwa Telecom Co., Ltd./OU=ePKI Root Certification
-    Authority
-Issuer: /ePKI Root Certification Authority - G2/C=TW/O=Chunghwa Telecom Co.,
-    Ltd.
-	Signature algorithm: RSA / SHA256
-Details:
-	Public key: RSA-4096
-	Serial number: 269677336687240111117627827670483958575
-	AKI: 72:5B:BA:AA:72:38:EE:25:90:24:B5:94:22:FA:09:88:CA:8B:0A:FB
-	SKI: 1E:0C:F7:B6:67:F2:E1:92:26:09:45:C0:55:39:2E:77:3F:42:4A:A2
-	Valid from: 2015-11-17T08:31:41+0000
-	     until: 2034-12-20T02:31:27+0000
-	Key usages: cert sign, crl sign
-	Basic constraints: valid, is a CA certificate
-	SANs (0):
-	1 AIA:
-		http://eca.hinet.net/repository/Certs/IssuedToThisCA.p7b
-	OCSP server:
-		- http://ocsp.eca.hinet.net/OCSP/ocspG2sha2
-CERTIFICATE
 Subject: /ePKI Root Certification Authority - G2/C=TW/O=Chunghwa Telecom Co.,
     Ltd.
 Issuer: /C=TW/O=Chunghwa Telecom Co., Ltd./OU=ePKI Root Certification
diff --git a/int-bundle.crt b/int-bundle.crt
index 6b257259..ec222300 100644
--- a/int-bundle.crt
+++ b/int-bundle.crt
@@ -6271,89 +6271,6 @@ fEoIXppf8vB10x3mNeBW4L+KFVPATupuTQarDILbbpVObH8RtXk6nis3+G1yDn5i
 nNKFefD+IxxpmvL+aPWgT+IpfdSnWTsviER93t9Z+XTtKie9vSs=
 -----END CERTIFICATE-----
 -----BEGIN CERTIFICATE-----
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------END CERTIFICATE-----
------BEGIN CERTIFICATE-----
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------END CERTIFICATE-----
------BEGIN CERTIFICATE-----
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