diff --git a/rainbowadn/testing/__init__.py b/rainbowadn/testing/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/rainbowadn/testing/failresolver.py b/rainbowadn/testing/failresolver.py
new file mode 100644
index 0000000..a65d7df
--- /dev/null
+++ b/rainbowadn/testing/failresolver.py
@@ -0,0 +1,6 @@
+from rainbowadn.hashing.hashresolver import HashResolver
+
+
+class FailResolver(HashResolver):
+    def _resolve(self, point: bytes) -> bytes:
+        raise TypeError('fail-resolver always fails')