diff --git a/Makefile b/Makefile
index 317a4b446f9a1cc4c084d69e4a2b7e86a4431eb6..0327d59031c8bb62402c8ea340ac7c01e5f4b5d8 100644
--- a/Makefile
+++ b/Makefile
@@ -21,3 +21,6 @@ check:
 
 test:
 	python -m pytest
+
+clean:
+	-rm -r $(CACHE_DIR)/*
diff --git a/cache.py b/cache.py
index 53be5aabc8ce74aaac2b066e1b98169e87553bef..d46342d64361a027244670e11d8d4242e584894b 100644
--- a/cache.py
+++ b/cache.py
@@ -28,10 +28,12 @@ def parse_puppet(s: str) -> dict[str, Any]:
     hash = hashlib.sha256(s.encode('UTF-8'))
     digest = hash.hexdigest()
     if record := r.get(digest):
-        return json.loads(record)
+        data = json.loads(record)
     else:
         almost_data = parse_puppet_for_real(s)
         hash = hashlib.sha256(almost_data)
         r.set(digest, almost_data)
         data = json.loads(almost_data)
-        return data
+    if type(data) != dict:
+        raise Exception("Weird data returned from puppet parse")
+    return data
diff --git a/main.py b/main.py
index 1cf91c2fcd13a70888f5e45184f9988ad0895c1c..5e8ca79f7b377b119376c0fb7df384fc2ba589fa 100644
--- a/main.py
+++ b/main.py
@@ -21,9 +21,10 @@ from typing import (
     Tuple,
 )
 
-HashEntry: TypeAlias  = Union[Tuple[Literal['=>'], str, Any],
-                              Tuple[Literal['+>'], str, Any],
-                              Tuple[Literal['splat-hash'], Any]]
+
+HashEntry: TypeAlias = Union[Tuple[Literal['=>'], str, Any],
+                             Tuple[Literal['+>'], str, Any],
+                             Tuple[Literal['splat-hash'], Any]]
 
 match sys.argv:
     case [_, d, *_]:
@@ -38,6 +39,7 @@ data = info
 
 param_doc: dict[str, str] = {}
 
+
 def print_hash(hash: list[HashEntry],
                indent: int,
                context: list[str]) -> None:
diff --git a/merge-json.py b/merge-json.py
index 65831da2012c87ef9de2cdc78d3e891fd62d58e6..0998d887248dee761d9b3c6e209f0ff59d33b9fd 100755
--- a/merge-json.py
+++ b/merge-json.py
@@ -38,7 +38,7 @@ def merge_dicts(objects: list[str]) -> dict[Any, list]:
     return merged
 
 
-def __main():
+def __main() -> None:
     import argparse
     parser = argparse.ArgumentParser()
     parser.add_argument('--out', action='store')