tests BUGFIX unused macro for tests
diff --git a/tests/config.h.in b/tests/config.h.in
index 864de67..2136c1b 100644
--- a/tests/config.h.in
+++ b/tests/config.h.in
@@ -12,6 +12,12 @@
  *     https://opensource.org/licenses/BSD-3-Clause
  */
 
+#ifdef __GNUC__
+#  define UNUSED(x) UNUSED_ ## x __attribute__((__unused__))
+#else
+#  define UNUSED(x) UNUSED_ ## x
+#endif
+
 #define TESTS_DIR "@CMAKE_SOURCE_DIR@/tests/"
 
 @SSH_MACRO@