diff --git a/client/client.go b/client/client.go
index e4ecdb4960..901e6c0bf1 100644
--- a/client/client.go
+++ b/client/client.go
@@ -145,7 +145,7 @@ func (r *NotaryRepository) Initialize(rootKeyID string) error {
 
 	// Hard-coded policy: the generated certificate expires in 10 years.
 	startTime := time.Now()
-	rootCert, err := cryptoservice.GenerateCertificate(privKey, r.gun, startTime, startTime.Add(time.Hour*24*365*10))
+	rootCert, err := cryptoservice.GenerateCertificate(privKey, r.gun, startTime, startTime.AddDate(10, 0, 0))
 
 	if err != nil {
 		return err
diff --git a/trustmanager/yubikey/yubikeystore.go b/trustmanager/yubikey/yubikeystore.go
index 23fa23341e..a10048367a 100644
--- a/trustmanager/yubikey/yubikeystore.go
+++ b/trustmanager/yubikey/yubikeystore.go
@@ -220,7 +220,7 @@ func addECDSAKey(
 
 	// Hard-coded policy: the generated certificate expires in 10 years.
 	startTime := time.Now()
-	template, err := trustmanager.NewCertificate(role, startTime, startTime.Add(time.Hour*24*365*10))
+	template, err := trustmanager.NewCertificate(role, startTime, startTime.AddDate(10, 0, 0))
 	if err != nil {
 		return fmt.Errorf("failed to create the certificate template: %v", err)
 	}