diff --git a/test/todo-datalog.rkt.fail b/test/todo-datalog.rkt.fail
new file mode 100644
index 0000000..d9ff448
--- /dev/null
+++ b/test/todo-datalog.rkt.fail
@@ -0,0 +1,10 @@
+#lang repltest datalog
+parent(amy, anabella).
+parent(john, anabella).
+parent(anabella, jack).
+parent(jack, ted).
+
+grandparent(X, Z) :- parent(X, Y), parent(Y, Z).
+
+> grandparent(X, ted)?
+grandparent(anabella, ted).
\ No newline at end of file