diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index cf9583c..292e931 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -1710,8 +1710,12 @@
     else
         alg = PSA_ALG_TLS12_PSK_TO_MS(PSA_ALG_SHA_256);
 
+#if defined(MBEDTLS_SSL_PROTO_TLS1_3)
     psa_set_key_usage_flags( &key_attributes,
                              PSA_KEY_USAGE_DERIVE | PSA_KEY_USAGE_EXPORT );
+#else
+    psa_set_key_usage_flags( &key_attributes, PSA_KEY_USAGE_DERIVE );
+#endif
     psa_set_key_algorithm( &key_attributes, alg );
     psa_set_key_type( &key_attributes, PSA_KEY_TYPE_DERIVE );