diff --git a/crates/aiken-lang/src/tipo.rs b/crates/aiken-lang/src/tipo.rs
index 5eaf7fa6..79f03902 100644
--- a/crates/aiken-lang/src/tipo.rs
+++ b/crates/aiken-lang/src/tipo.rs
@@ -531,6 +531,7 @@ impl TypeVar {
     pub fn get_inner_types(&self) -> Vec<Rc<Type>> {
         match self {
             Self::Link { tipo } => tipo.get_inner_types(),
+            Self::Unbound { .. } => vec![],
             var => {
                 vec![Type::Var {
                     tipo: RefCell::new(var.clone()).into(),
diff --git a/examples/acceptance_tests/066/lib/tests.ak b/examples/acceptance_tests/066/lib/tests.ak
index 69e69e01..6e3187fc 100644
--- a/examples/acceptance_tests/066/lib/tests.ak
+++ b/examples/acceptance_tests/066/lib/tests.ak
@@ -18,8 +18,5 @@ fn sum_list(list: List<Schema>) -> Int {
 }
 
 test foo() {
-  // False
-  // Can't enable the "real" test because it puts the UPLC evaluator in an infinite loop.
-  // -
   sum(List([List([Integer(1), Integer(2)]), Integer(3), Integer(4)])) == 10
 }