diff --git a/src/macros.py b/src/macros.py
index 1e436a0..c160b49 100644
--- a/src/macros.py
+++ b/src/macros.py
@@ -92,6 +92,7 @@
 macro IS_SCRIPT(arg)            = (%_ClassOf(arg) === 'Script');
 macro IS_ARGUMENTS(arg)         = (%_ClassOf(arg) === 'Arguments');
 macro IS_GLOBAL(arg)            = (%_ClassOf(arg) === 'global');
+macro IS_UNDETECTABLE(arg)      = (%_IsUndetectableObject(arg));
 macro FLOOR(arg)                = $floor(arg);
 
 # Inline macros. Use %IS_VAR to make sure arg is evaluated only once.