diff --git a/backend/src/services/certificate-authority/internal/internal-certificate-authority-fns.ts b/backend/src/services/certificate-authority/internal/internal-certificate-authority-fns.ts
index 77514f096..9e2d9f539 100644
--- a/backend/src/services/certificate-authority/internal/internal-certificate-authority-fns.ts
+++ b/backend/src/services/certificate-authority/internal/internal-certificate-authority-fns.ts
@@ -84,7 +84,7 @@ export const InternalCertificateAuthorityFns = ({
 
     const caCertObj = new x509.X509Certificate(decryptedCaCert);
     const notBeforeDate = new Date();
-    const notAfterDate = new Date(new Date().getTime() + ms(subscriber.ttl));
+    const notAfterDate = new Date(new Date().getTime() + ms(subscriber.ttl ?? "0"));
     const caCertNotBeforeDate = new Date(caCertObj.notBefore);
     const caCertNotAfterDate = new Date(caCertObj.notAfter);