diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index ce14c7d..465b921 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -5762,7 +5762,7 @@
 
 /* NOTICE: see above */
 #if defined(MBEDTLS_SSL_PROTO_TLS1_2)
-static uint16_t ssl_tls12_preset_default_sig_algs[] = {
+static const uint16_t ssl_tls12_preset_default_sig_algs[] = {
 
 #if defined(MBEDTLS_MD_CAN_SHA512)
 #if defined(MBEDTLS_KEY_EXCHANGE_ECDSA_CERT_REQ_ALLOWED_ENABLED)