diff --git a/tests/test_cache_function.py b/tests/test_cache_function.py
index 4a635734f..519366be3 100644
--- a/tests/test_cache_function.py
+++ b/tests/test_cache_function.py
@@ -1,28 +1,31 @@
+from __future__ import annotations
+
 from timeit import timeit
 
 import proselint
 from proselint import memoizer
 
+DEMO_PATH = proselint.path / "demo.md"
+DEMO_TEXT = DEMO_PATH.open(encoding="utf-8", errors="replace").read()
+
 
-def test_speed():
-    """Compare uncached vs cached reads"""
-    repetitions = 2
+def test_speed() -> None:
+    """Compare uncached vs cached reads."""
+    repetitions = 3
 
     demo_path = proselint.path / "demo.md"
+    _text = DEMO_TEXT
     _code = "errors = proselint.tools.lint(_text)"
     _setup = "import proselint"
-    with demo_path.open(encoding="utf-8", errors="replace") as demo_fh:
-        _text = demo_fh.read()
-
     # make sure it works
-    memoizer.cache.clear()
-    errors = proselint.tools.lint(_text)
+    memoizer.cache.clear_internal()
+    errors = proselint.tools.lint(DEMO_TEXT)
     assert len(errors) > 0
 
     # without cache
     _dur1 = 0.0
     for _ in range(repetitions):
-        memoizer.cache.clear()
+        memoizer.cache.clear_internal()
         _dur1 += timeit(_code, setup=_setup, globals=locals(), number=1)
 
     # with cache
@@ -33,20 +36,21 @@ def test_speed():
     # without cache, confirmation
     _dur3 = 0.0
     for _ in range(repetitions):
-        memoizer.cache.clear()
+        memoizer.cache.clear_internal()
         _dur3 += timeit(_code, setup=_setup, globals=locals(), number=1)
 
     assert _dur2 < 0.7 * _dur1
     assert _dur2 < 0.7 * _dur3
 
 
-def test_consistency():
-    """Compare result-count"""
-    demo_path = proselint.path / "demo.md"
-    demo_fh = demo_path.open(encoding="utf-8", errors="replace")
-    demo_str = demo_fh.read()
-    memoizer.cache.clear()
-    errors_a = proselint.tools.lint(demo_str)
-    errors_b = proselint.tools.lint(demo_str)
-
-    assert len(errors_a) == len(errors_b)
+def test_consistency() -> None:
+    """Compare result count from cached and uncached runs."""
+    memoizer.cache.clear_internal()
+    errors_a = proselint.tools.lint(DEMO_TEXT)
+    errors_b = proselint.tools.lint(DEMO_TEXT)
+    assert len(errors_a) == len(
+        list(memoizer.cache.values())[-1]
+    ), "Errors were not cached correctly - quantity mismatch."
+    assert len(errors_a) == len(
+        errors_b
+    ), "Errors were not cached correctly - differing output."