diff --git a/ragatouille/data/training_data_processor.py b/ragatouille/data/training_data_processor.py
index 689c4a1..696005a 100644
--- a/ragatouille/data/training_data_processor.py
+++ b/ragatouille/data/training_data_processor.py
@@ -33,11 +33,12 @@ def process_raw_data(
         negative_label: int = 0,
         hard_negative_minimum_rank: int = 10,
     ):
-        self.negative_miner.min_rank = hard_negative_minimum_rank
         if self.negative_miner is None and mine_hard_negatives:
             raise ValueError(
                 "mine_hard_negatives is True but no negative miner was provided!"
             )
+        if self.negative_miner:
+            self.negative_miner.min_rank = hard_negative_minimum_rank
         if data_type == "pairs":
             self._process_raw_pairs(
                 raw_data=raw_data,
diff --git a/ragatouille/models/colbert.py b/ragatouille/models/colbert.py
index 4d73c62..3b65289 100644
--- a/ragatouille/models/colbert.py
+++ b/ragatouille/models/colbert.py
@@ -11,6 +11,7 @@
 from colbert import Indexer, IndexUpdater, Searcher, Trainer
 from colbert.infra import ColBERTConfig, Run, RunConfig
 from colbert.modeling.checkpoint import Checkpoint
+
 from ragatouille.models.base import LateInteractionModel
 
 
diff --git a/tests/test_training_data_processor.py b/tests/test_training_data_processor.py
new file mode 100644
index 0000000..c51a092
--- /dev/null
+++ b/tests/test_training_data_processor.py
@@ -0,0 +1,36 @@
+from unittest.mock import MagicMock
+
+import pytest
+
+from ragatouille.data import TrainingDataProcessor
+
+
+@pytest.fixture
+def collection():
+    return ["doc1", "doc2", "doc3"]
+
+
+@pytest.fixture
+def queries():
+    return ["query1", "query2"]
+
+
+def test_process_raw_data_without_miner(collection, queries):
+    processor = TrainingDataProcessor(collection, queries, None)
+    processor._process_raw_pairs = MagicMock(return_value=None)
+
+    processor.process_raw_data(
+        raw_data=[], data_type="pairs", data_dir="./", mine_hard_negatives=False
+    )
+
+    processor._process_raw_pairs.assert_called_once()
+
+
+def test_process_raw_data_with_miner(collection, queries):
+    negative_miner = MagicMock()
+    processor = TrainingDataProcessor(collection, queries, negative_miner)
+    processor._process_raw_pairs = MagicMock(return_value=None)
+
+    processor.process_raw_data(raw_data=[], data_type="pairs", data_dir="./")
+
+    processor._process_raw_pairs.assert_called_once()