Fix for unused variable warning
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index f5dcdee..4424f56 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -7097,6 +7097,7 @@
     memset( conf, 0, sizeof( mbedtls_ssl_config ) );
 }
 
+#if defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
 static int ssl_preset_default_hashes[] = {
 #if defined(MBEDTLS_SHA512_C)
     MBEDTLS_MD_SHA512,
@@ -7111,6 +7112,7 @@
 #endif
     MBEDTLS_MD_NONE
 };
+#endif
 
 static int ssl_preset_suiteb_ciphersuites[] = {
     MBEDTLS_TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,