diff --git a/lib/modules/Function.pmod b/lib/modules/Function.pmod
new file mode 100644
index 0000000000000000000000000000000000000000..7ab3243845723be2f27450c71dfcdf6b7032eefd
--- /dev/null
+++ b/lib/modules/Function.pmod
@@ -0,0 +1 @@
+constant defined = __builtin.function_defined;