diff --git a/examples/acceptance_tests/053/aiken.lock b/examples/acceptance_tests/053/aiken.lock
new file mode 100644
index 00000000..3a78b1e7
--- /dev/null
+++ b/examples/acceptance_tests/053/aiken.lock
@@ -0,0 +1,5 @@
+# This file was generated by Aiken
+# You typically do not need to edit this file
+
+requirements = []
+packages = []
diff --git a/examples/acceptance_tests/053/aiken.toml b/examples/acceptance_tests/053/aiken.toml
new file mode 100644
index 00000000..e219f43a
--- /dev/null
+++ b/examples/acceptance_tests/053/aiken.toml
@@ -0,0 +1,3 @@
+name = 'aiken-lang/acceptance_test_053'
+version = '0.0.0'
+description = ''
diff --git a/examples/acceptance_tests/053/lib/tests.ak b/examples/acceptance_tests/053/lib/tests.ak
new file mode 100644
index 00000000..e4f25625
--- /dev/null
+++ b/examples/acceptance_tests/053/lib/tests.ak
@@ -0,0 +1,16 @@
+pub type LinkedList<a> {
+  Empty
+  Node(a, LinkedList<a>)
+}
+
+pub fn size(t: LinkedList<alg>) -> Int {
+  when t is {
+    Empty -> 0
+    Node(_, tail) -> 1 + size(tail)
+  }
+}
+
+test foo() {
+  let xs = Node(0, Node(1, Node(2, Empty)))
+  size(xs) == 3
+}