diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 588cbc4..6e01494 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -4769,6 +4769,12 @@
                           const ssl_ciphersuite_t *ciphersuite,
                           int cert_endpoint )
 {
+#if !defined(POLARSSL_X509_CHECK_KEY_USAGE)
+    ((void) cert);
+    ((void) ciphersuite);
+    ((void) cert_endpoint);
+#endif
+
 #if defined(POLARSSL_X509_CHECK_KEY_USAGE)
     int usage = 0;
 #endif