diff --git a/CHANGELOG.md b/CHANGELOG.md
index fb7afa81..240185d1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -18,6 +18,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - The `--output` option has been split into two options, `--output_dir` and `--output_root`.
 - The `--validation_peak_path` is now optional when training; if `--validation_peak_path` is not set then the `train_peak_path` will also be used for validation.
 - The `tb_summarywriter` config option is now a boolean config option, and if set to true the TensorBoard summary will be written to a sub-directory of the output directory named `tensorboard`.
+- The Casanovo model peptide level score is now reported as the geometric mean of the raw amino acid scores, rather then the arithmetic mean.
 
 ### Fixed
 
diff --git a/tests/unit_tests/test_unit.py b/tests/unit_tests/test_unit.py
index 88266813..985cfb4b 100644
--- a/tests/unit_tests/test_unit.py
+++ b/tests/unit_tests/test_unit.py
@@ -446,6 +446,11 @@ def test_aa_pep_score():
     np.testing.assert_array_equal(aa_scores, np.asarray([0.0, 0.25, 0.5]))
     assert peptide_score == pytest.approx(-1.0)
 
+    aa_scores_raw = np.asarray([1.0, 0.25])
+    aa_scores, peptide_score = _aa_pep_score(aa_scores_raw, True)
+    np.testing.assert_array_equal(aa_scores, np.asarray([0.75, 0.375]))
+    assert peptide_score == pytest.approx(0.5)
+
 
 def test_beam_search_decode():
     """