diff --git a/examples/run_seq2seq_finetuning_test.py b/examples/run_seq2seq_finetuning_test.py
index e59f016da4d..77dc58666cb 100644
--- a/examples/run_seq2seq_finetuning_test.py
+++ b/examples/run_seq2seq_finetuning_test.py
@@ -21,43 +21,21 @@ class DataLoaderTest(unittest.TestCase):
     def setUp(self):
         self.block_size = 10
 
-    def test_truncate_source_and_target_too_small(self):
-        """ When the sum of the lengths of the source and target sequences is
-        smaller than the block size (minus the number of special tokens), skip the example. """
-        src_seq = [1, 2, 3, 4]
-        tgt_seq = [5, 6]
-        self.assertEqual(_fit_to_block_size(src_seq, tgt_seq, self.block_size), None)
+    def test_truncate_sequence_too_small(self):
+        """ Pad the sequence with 0 if the sequence is smaller than the block size."""
+        sequence = [1, 2, 3, 4]
+        expected_output = [1, 2, 3, 4, 0, 0, 0, 0, 0, 0]
+        self.assertEqual(_fit_to_block_size(sequence, self.block_size), expected_output)
 
-    def test_truncate_source_and_target_fit_exactly(self):
-        """ When the sum of the lengths of the source and target sequences is
-        equal to the block size (minus the number of special tokens), return the
-        sequences unchanged. """
-        src_seq = [1, 2, 3, 4]
-        tgt_seq = [5, 6, 7]
-        fitted_src, fitted_tgt = _fit_to_block_size(src_seq, tgt_seq, self.block_size)
-        self.assertListEqual(src_seq, fitted_src)
-        self.assertListEqual(tgt_seq, fitted_tgt)
+    def test_truncate_sequence_fit_exactly(self):
+        sequence = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
+        expected_output = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
+        self.assertEqual(_fit_to_block_size(sequence, self.block_size), expected_output)
 
-    def test_truncate_source_too_big_target_ok(self):
-        src_seq = [1, 2, 3, 4, 5, 6]
-        tgt_seq = [1, 2]
-        fitted_src, fitted_tgt = _fit_to_block_size(src_seq, tgt_seq, self.block_size)
-        self.assertListEqual(fitted_src, [1, 2, 3, 4, 5])
-        self.assertListEqual(fitted_tgt, fitted_tgt)
-
-    def test_truncate_target_too_big_source_ok(self):
-        src_seq = [1, 2, 3, 4]
-        tgt_seq = [1, 2, 3, 4]
-        fitted_src, fitted_tgt = _fit_to_block_size(src_seq, tgt_seq, self.block_size)
-        self.assertListEqual(fitted_src, src_seq)
-        self.assertListEqual(fitted_tgt, [1, 2, 3])
-
-    def test_truncate_source_and_target_too_big(self):
-        src_seq = [1, 2, 3, 4, 5, 6, 7]
-        tgt_seq = [1, 2, 3, 4, 5, 6, 7]
-        fitted_src, fitted_tgt = _fit_to_block_size(src_seq, tgt_seq, self.block_size)
-        self.assertListEqual(fitted_src, [1, 2, 3, 4, 5])
-        self.assertListEqual(fitted_tgt, [1, 2])
+    def test_truncate_sequence_too_big(self):
+        sequence = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13]
+        expected_output = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
+        self.assertEqual(_fit_to_block_size(sequence, self.block_size), expected_output)
 
     def test_process_story_no_highlights(self):
         """ Processing a story with no highlights should raise an exception.