diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c
index 7fd56df8b919..99fe28663f94 100644
--- a/crypto/asymmetric_keys/x509_public_key.c
+++ b/crypto/asymmetric_keys/x509_public_key.c
@@ -128,6 +128,11 @@ int x509_check_for_self_signed(struct x509_certificate *cert)
 			goto out;
 	}
 
+	if (cert->unsupported_sig) {
+		ret = 0;
+		goto out;
+	}
+
 	ret = public_key_verify_signature(cert->pub, cert->sig);
 	if (ret < 0) {
 		if (ret == -ENOPKG) {