diff --git a/book/source/17-zoom_certificates.md b/book/source/17-zoom_certificates.md
index 485a612..acac0d1 100644
--- a/book/source/17-zoom_certificates.md
+++ b/book/source/17-zoom_certificates.md
@@ -257,7 +257,7 @@ The first fields of a packet are governed by the general [Packet Syntax](https:/
 
 **Signature packet syntax**
 
-The packet type ID (“2”) defines the semantics of the remaining data in the packet. In this case, as it indicates a [Signature packet](https://www.ietf.org/archive/id/draft-ietf-openpgp-crypto-refresh-10.html#signature-packet), the following data is specific to this packet type.
+The packet type ID (“2”) defines the semantics of the remaining data in the packet. In this case, as it indicates a [Signature packet](https://www.ietf.org/archive/id/draft-ietf-openpgp-crypto-refresh-10.html#signature-packet), the following data is specific to this packet type:
 
 - `version: 0x06`: This is a version 6 signature.