diff --git a/src/serve.py b/src/serve.py
index 76cddf5..c1c9deb 100644
--- a/src/serve.py
+++ b/src/serve.py
@@ -60,7 +60,7 @@ def make_prediction_server(predict_fn: Callable):
 
                 logging.debug("Running predictor on document...")
                 predictions = predict_fn(pdf)
-                logging.debug(f"Found {sum(map(len, predictions))} images in document.")
+                logging.debug(f"Found {len(predictions)} images in document.")
                 response = jsonify(list(predictions))
 
                 return response