diff --git a/CCU_validation_scoring/__init__.py b/CCU_validation_scoring/__init__.py
index a36cd87..62118e2 100644
--- a/CCU_validation_scoring/__init__.py
+++ b/CCU_validation_scoring/__init__.py
@@ -1,3 +1,3 @@
-__all__ = ['validate_submission','validate_reference','score_submission','score_norm_emotion','score_valence_arousal','score_changepoint','preprocess_referece']
+__all__ = ['validate_submission','validate_reference','score_submission','score_norm_emotion','score_valence_arousal','score_changepoint','preprocess_reference']
 
 __version__ = '1.2.0'
diff --git a/CCU_validation_scoring/score_changepoint.py b/CCU_validation_scoring/score_changepoint.py
index d8227ca..adab9fb 100644
--- a/CCU_validation_scoring/score_changepoint.py
+++ b/CCU_validation_scoring/score_changepoint.py
@@ -216,8 +216,9 @@ def compute_multiclass_cp_pr(ref, hyp, delta_cp_text_thresholds = 100, delta_cp_
     """
     # Initialize
 
-    scores = {}
-    [ scores.setdefault(iout, pd.DataFrame([], columns = ['type', 'ap', 'precision', 'recall', 'llr'])) for iout in delta_cp_text_thresholds + delta_cp_time_thresholds ]
+    from collections import defaultdict
+    scores = defaultdict(list)
+    # [ scores.setdefault(iout, pd.DataFrame([], columns = ['type', 'ap', 'precision', 'recall', 'llr'])) for iout in delta_cp_text_thresholds + delta_cp_time_thresholds ]
 
     ### Capture the noscores for later use
     ref_noscore = ref.loc[ref.impact_scalar == 'NO_SCORE_REGION']