diff --git a/library/ssl_tls13_keys.c b/library/ssl_tls13_keys.c
index c035504..a030b65 100644
--- a/library/ssl_tls13_keys.c
+++ b/library/ssl_tls13_keys.c
@@ -568,7 +568,8 @@
     mbedtls_ssl_context *ssl )
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
-    mbedtls_md_type_t const md_type = ssl->handshake->ciphersuite_info->mac;
+    mbedtls_ssl_handshake_params *handshake = ssl->handshake;
+    mbedtls_md_type_t const md_type = handshake->ciphersuite_info->mac;
 #if defined(MBEDTLS_DEBUG_C)
     mbedtls_md_info_t const * const md_info = mbedtls_md_info_from_type( md_type );
     size_t const md_size = mbedtls_md_get_size( md_info );
@@ -578,9 +579,9 @@
      * Compute MasterSecret
      */
     ret = mbedtls_ssl_tls1_3_evolve_secret( md_type,
-                    ssl->handshake->tls1_3_master_secrets.handshake,
+                    handshake->tls1_3_master_secrets.handshake,
                     NULL, 0,
-                    ssl->handshake->tls1_3_master_secrets.app );
+                    handshake->tls1_3_master_secrets.app );
     if( ret != 0 )
     {
         MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_tls1_3_evolve_secret", ret );
@@ -588,7 +589,7 @@
     }
 
     MBEDTLS_SSL_DEBUG_BUF( 4, "Master secret",
-             ssl->handshake->tls1_3_master_secrets.app, md_size );
+             handshake->tls1_3_master_secrets.app, md_size );
 
     return( 0 );
 }
@@ -690,7 +691,7 @@
 
 exit:
 
-    mbedtls_platform_zeroize( transcript, sizeof( transcript) );
+    mbedtls_platform_zeroize( transcript, sizeof( transcript ) );
     return( ret );
 }
 
@@ -1116,13 +1117,14 @@
                                         mbedtls_ssl_key_set *traffic_keys )
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+    mbedtls_ssl_handshake_params *handshake = ssl->handshake;
 
     /* Address at which to store the application secrets */
     mbedtls_ssl_tls1_3_application_secrets * const app_secrets =
         &ssl->session_negotiate->app_secrets;
 
     /* Holding the transcript up to and including the ServerFinished */
-    unsigned char transcript[MBEDTLS_MD_MAX_SIZE];
+    unsigned char transcript[MBEDTLS_TLS1_3_MD_MAX_SIZE];
     size_t transcript_len;
 
     /* Variables relating to the hash for the chosen ciphersuite. */
@@ -1139,11 +1141,11 @@
     /* Extract basic information about hash and ciphersuite */
 
     cipher_info = mbedtls_cipher_info_from_type(
-                                  ssl->handshake->ciphersuite_info->cipher );
+                                  handshake->ciphersuite_info->cipher );
     keylen = cipher_info->key_bitlen / 8;
     ivlen = cipher_info->iv_size;
 
-    md_type = ssl->handshake->ciphersuite_info->mac;
+    md_type = handshake->ciphersuite_info->mac;
     md_info = mbedtls_md_info_from_type( md_type );
     md_size = mbedtls_md_get_size( md_info );
 
@@ -1159,7 +1161,7 @@
     /* Compute application secrets from master secret and transcript hash. */
 
     ret = mbedtls_ssl_tls1_3_derive_application_secrets( md_type,
-                                   ssl->handshake->tls1_3_master_secrets.app,
+                                   handshake->tls1_3_master_secrets.app,
                                    transcript, transcript_len,
                                    app_secrets );
     if( ret != 0 )
@@ -1197,16 +1199,16 @@
         ssl->f_export_keys( ssl->p_export_keys,
                 MBEDTLS_SSL_KEY_EXPORT_TLS13_CLIENT_APPLICATION_TRAFFIC_SECRET,
                 app_secrets->client_application_traffic_secret_N, md_size,
-                ssl->handshake->randbytes + 32,
-                ssl->handshake->randbytes,
+                handshake->randbytes + 32,
+                handshake->randbytes,
                 MBEDTLS_SSL_TLS_PRF_NONE /* TODO: this should be replaced by
                                             a new constant for TLS 1.3! */ );
 
         ssl->f_export_keys( ssl->p_export_keys,
                 MBEDTLS_SSL_KEY_EXPORT_TLS13_SERVER_APPLICATION_TRAFFIC_SECRET,
                 app_secrets->server_application_traffic_secret_N, md_size,
-                ssl->handshake->randbytes + 32,
-                ssl->handshake->randbytes,
+                handshake->randbytes + 32,
+                handshake->randbytes,
                 MBEDTLS_SSL_TLS_PRF_NONE /* TODO: this should be replaced by
                                             a new constant for TLS 1.3! */ );
     }
@@ -1224,7 +1226,7 @@
 
  cleanup:
 
-    mbedtls_platform_zeroize( transcript, sizeof(transcript) );
+    mbedtls_platform_zeroize( transcript, sizeof( transcript ) );
     return( ret );
 }