diff --git a/domains/cert/rsa2048/index.html b/domains/cert/rsa2048/index.html
index 7fa7fa6b..3ec2af3e 100644
--- a/domains/cert/rsa2048/index.html
+++ b/domains/cert/rsa2048/index.html
@@ -12,5 +12,5 @@ <h1 style="font-size: 8vw;">
 </div>
 
 <div id="footer" style="font-size: 2.75vw;">
-  This site uses an 2048-bit RSA key for key exchange.
+  This site uses a 2048-bit RSA key for key exchange.
 </div>