diff --git a/tests/unit/core/operation/decomposition/test_column_sampling_decomposition.py b/tests/unit/core/operation/decomposition/test_column_sampling_decomposition.py
index baa951fa0..d69fee3d5 100644
--- a/tests/unit/core/operation/decomposition/test_column_sampling_decomposition.py
+++ b/tests/unit/core/operation/decomposition/test_column_sampling_decomposition.py
@@ -16,7 +16,7 @@ def sample_ts():
 
 
 def test_fit_transform(sample_matrix):
-    rank = 2
+    rank = 1
     cur = CURDecomposition(rank)
     result = cur.fit_transform(sample_matrix)
     approximated = result[0]