diff --git a/library/ssl_tls13_server.c b/library/ssl_tls13_server.c
index 378ce8f..051afa2 100644
--- a/library/ssl_tls13_server.c
+++ b/library/ssl_tls13_server.c
@@ -700,6 +700,8 @@
     MBEDTLS_SSL_DEBUG_MSG( 4, ( "sent selected_identity: %u",
                                 ssl->handshake->selected_identity ) );
 
+    mbedtls_ssl_tls13_set_hs_sent_ext_mask( ssl, MBEDTLS_TLS_EXT_PRE_SHARED_KEY );
+
     return( 0 );
 }
 
@@ -1812,6 +1814,9 @@
 
     *out_len = 6;
 
+    mbedtls_ssl_tls13_set_hs_sent_ext_mask(
+        ssl, MBEDTLS_TLS_EXT_SUPPORTED_VERSIONS );
+
     return( 0 );
 }
 
@@ -1918,6 +1923,8 @@
 
     *out_len = p - buf;
 
+    mbedtls_ssl_tls13_set_hs_sent_ext_mask( ssl, MBEDTLS_TLS_EXT_KEY_SHARE );
+
     return( 0 );
 }
 
@@ -1982,6 +1989,8 @@
 
     *out_len = 6;
 
+    mbedtls_ssl_tls13_set_hs_sent_ext_mask( ssl, MBEDTLS_TLS_EXT_KEY_SHARE );
+
     return( 0 );
 }