diff --git a/arithmetic_analysis/lu_decomposition.py b/arithmetic_analysis/lu_decomposition.py
index ef37d1b7b..5bb631758 100644
--- a/arithmetic_analysis/lu_decomposition.py
+++ b/arithmetic_analysis/lu_decomposition.py
@@ -6,10 +6,9 @@ Reference:
 from typing import Tuple
 
 import numpy as np
-from numpy import ndarray
 
 
-def lower_upper_decomposition(table: ndarray) -> Tuple[ndarray, ndarray]:
+def lower_upper_decomposition(table: np.ndarray) -> Tuple[np.ndarray, np.ndarray]:
     """Lower-Upper (LU) Decomposition
 
     Example: