diff --git a/volia/core/measures.py b/volia/core/measures.py
index 4e5e94a..8ade117 100644
--- a/volia/core/measures.py
+++ b/volia/core/measures.py
@@ -185,8 +185,9 @@ def purity_score(y_truth, y_hat):
     
 
     count_matrix = compute_count_matrix(y_truth, y_hat)
-    _, purity_cluster_score = compute_purity_score(count_matrix, 1)
-    _, purity_class_score = cluster_purity = compute_purity_score(count_matrix, 0)
+
+    purity_cluster_score = compute_purity_score(count_matrix, 1)
+    purity_class_score = compute_purity_score(count_matrix, 0)
 
     K = np.sqrt(purity_cluster_score * purity_class_score)