diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index a956bab..660d548 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -6020,6 +6020,8 @@
             return( SSL_CERTIFICATE_SKIP );
         }
     }
+#else
+    ((void) authmode);
 #endif /* MBEDTLS_SSL_SRV_C */
 
     return( SSL_CERTIFICATE_EXPECTED );