diff --git a/security.md b/security.md
index 2b30d383..c3e82d86 100644
--- a/security.md
+++ b/security.md
@@ -31,7 +31,7 @@ These services are protected by [TLS](https://en.wikipedia.org/wiki/Transport_La
 
 * SMTP Submission (port 587). Mail users submit outbound mail through SMTP with STARTTLS on port 587.
 * IMAP/POP (ports 993, 995). Mail users check for incoming mail through IMAP or POP over TLS.
-* HTTPS (port 443). Webmail, the Echange/ActiveSync protocol, the administrative control panel, and any static hosted websites are accessed over HTTPS.
+* HTTPS (port 443). Webmail, the Exchange/ActiveSync protocol, the administrative control panel, and any static hosted websites are accessed over HTTPS.
 
 The services all follow these rules: