diff --git a/combo/utils/matrices.py b/combo/utils/matrices.py
index 7a982db7ecb8a0a19db0a30ce04024706d92697c..395e23d2b4628313551aa061328cbeef87895086 100644
--- a/combo/utils/matrices.py
+++ b/combo/utils/matrices.py
@@ -20,7 +20,6 @@ def extract_combo_matrices(predictions: List[Sentence],
     OUTPUT_DIRECTORY_MATRICES = serialization_dir / "combo_output" / "dependency_tree_matrices"
     OUTPUT_RELATION_LABEL_DISTRIBUTION = serialization_dir / "combo_output" / "label_distribution_matrices"
 
-    meta_sentences = []
     meta_ids = []
     meta_splits = []
     meta_file_names = []