diff --git a/library/ssl_tls13_client.c b/library/ssl_tls13_client.c
index 511f4cd..5abb18c 100644
--- a/library/ssl_tls13_client.c
+++ b/library/ssl_tls13_client.c
@@ -799,7 +799,7 @@
 #endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
 
 #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
-    /* Write server name extention */
+    /* Write server name extension */
     ret = mbedtls_ssl_write_hostname_ext( ssl, p, end, &output_len );
     if( ret != 0 )
         return( ret );