diff --git a/tests/rust-python-harness/strategies/e2e_benchmark/worker.py b/tests/rust-python-harness/strategies/e2e_benchmark/worker.py
index 89c5d1cd896..201a2c6339e 100644
--- a/tests/rust-python-harness/strategies/e2e_benchmark/worker.py
+++ b/tests/rust-python-harness/strategies/e2e_benchmark/worker.py
@@ -17,8 +17,11 @@ from .models import Invocation, Ready, Timing
 
 
 def file_sha256(path: Path) -> str:
+    digest: Final = hashlib.sha256()
     with path.open("rb") as source:
-        return hashlib.file_digest(source, "sha256").hexdigest()
+        for chunk in iter(lambda: source.read(256 * 1024), b""):
+            digest.update(chunk)
+    return digest.hexdigest()
 
 
 def _ready(response: OCRResponse) -> Ready: