diff --git a/book/source/06-signatures.md b/book/source/06-signatures.md
index 625e66b..903ae7b 100644
--- a/book/source/06-signatures.md
+++ b/book/source/06-signatures.md
@@ -108,7 +108,7 @@ They are formatted as key-value pairs, where the keys are defined as [subpacket
 
 ### Examples of signature subpackets
 - The [*issuer fingerprint*](https://www.ietf.org/archive/id/draft-ietf-openpgp-crypto-refresh-12.html#issuer-fingerprint-subpacket) subpacket encodes the fingerprint of the component key that issued the signature.
-- The [*key flags*](https://www.ietf.org/archive/id/draft-ietf-openpgp-crypto-refresh-12.html#name-key-flags) subpacket defines the capabilities are assigned to a component key within a certificate.
+- The [*key flags*](https://www.ietf.org/archive/id/draft-ietf-openpgp-crypto-refresh-12.html#name-key-flags) subpacket defines the capabilities that are assigned to a component key within a certificate.
 
 ### Hashed and unhashed signature subpackets