diff --git a/smx509/parser.go b/smx509/parser.go
index f7eaff0..42d4f8d 100644
--- a/smx509/parser.go
+++ b/smx509/parser.go
@@ -1063,7 +1063,7 @@ func ParseCertificates(der []byte) ([]*Certificate, error) {
 
 func ParseCertificatePEM(data []byte) (*Certificate, error) {
 	block, _ := pem.Decode(data)
-	if block == nil {
+	if block == nil || block.Type != "CERTIFICATE" {
 		return nil, errors.New("x509: failed to decode PEM block containing certificate")
 	}
 	return ParseCertificate(block.Bytes)