diff --git a/library/ssl_misc.h b/library/ssl_misc.h
index 2ad5965..d16b254 100644
--- a/library/ssl_misc.h
+++ b/library/ssl_misc.h
@@ -612,14 +612,18 @@
      */
 #if defined(MBEDTLS_SSL_PROTO_TLS1_3)
     uint8_t key_exchange_mode; /*!< Selected key exchange mode */
-    uint8_t tls13_kex_modes;   /*!< key exchange modes for TLS 1.3 */
 
     /** Number of HelloRetryRequest messages received/sent from/to the server. */
     int hello_retry_request_count;
+
 #if defined(MBEDTLS_SSL_SRV_C)
     /** selected_group of key_share extension in HelloRetryRequest message. */
     uint16_t hrr_selected_group;
+#if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED)
+    uint8_t tls13_kex_modes; /*!< Key exchange modes supported by the client */
+#endif
 #endif /* MBEDTLS_SSL_SRV_C */
+
 #endif /* MBEDTLS_SSL_PROTO_TLS1_3 */
 
 #if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
@@ -1770,6 +1774,7 @@
                    MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ALL ) );
 }
 
+#if defined(MBEDTLS_SSL_SRV_C) && defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED)
 /**
  * Given a list of key exchange modes, check if at least one of them is
  * supported.
@@ -1816,6 +1821,7 @@
     return( ! mbedtls_ssl_tls13_check_kex_modes( ssl,
                    MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ALL ) );
 }
+#endif /* MBEDTLS_SSL_SRV_C && MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED */
 
 /*
  * Helper functions to check the selected key exchange mode.