def: Add missing cmocka_set_message_output symbol
diff --git a/src/cmocka.def b/src/cmocka.def
index e00330e..607ad75 100644
--- a/src/cmocka.def
+++ b/src/cmocka.def
@@ -36,6 +36,7 @@
     _test_malloc
     _test_realloc
     _will_return
+    cmocka_set_message_output
     global_expect_assert_env
     global_expecting_assert
     global_last_failed_assert