diff --git a/attributecert/attributecert.go b/attributecert/attributecert.go
index ea4331b..b86b35f 100644
--- a/attributecert/attributecert.go
+++ b/attributecert/attributecert.go
@@ -37,6 +37,7 @@ var (
 	oidSignatureRSASha1   = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 5}
 	oidSignatureRSAPSS    = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 10}
 	oidSignatureRSASha256 = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 11}
+	oidSignatureRSASha384 = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 12}
 	oidSignatureEd25519   = asn1.ObjectIdentifier{1, 3, 101, 112}
 
 	oidSHA256 = asn1.ObjectIdentifier{2, 16, 840, 1, 101, 3, 4, 2, 1}
@@ -55,6 +56,7 @@ var signatureAlgorithmDetails = []struct {
 }{
 	{x509.SHA1WithRSA, "SHA1-RSA", oidSignatureRSASha1, x509.RSA, crypto.SHA1},
 	{x509.SHA256WithRSA, "SHA256-RSA", oidSignatureRSASha256, x509.RSA, crypto.SHA256},
+	{x509.SHA384WithRSA, "SHA384-RSA", oidSignatureRSASha384, x509.RSA, crypto.SHA384},
 	{x509.SHA256WithRSAPSS, "SHA256-RSAPSS", oidSignatureRSAPSS, x509.RSA, crypto.SHA256},
 	{x509.SHA384WithRSAPSS, "SHA384-RSAPSS", oidSignatureRSAPSS, x509.RSA, crypto.SHA384},
 	{x509.SHA512WithRSAPSS, "SHA512-RSAPSS", oidSignatureRSAPSS, x509.RSA, crypto.SHA512},