diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h
index b6f27a2..fda097e 100644
--- a/include/crypto/public_key.h
+++ b/include/crypto/public_key.h
@@ -33,6 +33,7 @@
 enum pkey_id_type {
 	PKEY_ID_PGP,		/* OpenPGP generated key ID */
 	PKEY_ID_X509,		/* X.509 arbitrary subjectKeyIdentifier */
+	PKEY_ID_PKCS7,		/* Signature in PKCS#7 message */
 	PKEY_ID_TYPE__LAST
 };