diff --git a/tests/test_sparse.py b/tests/test_sparse.py
index 184ae398..78ef158b 100644
--- a/tests/test_sparse.py
+++ b/tests/test_sparse.py
@@ -790,6 +790,13 @@ def test_sparse_array_indexing():
     sa[[0, 1]] = [[[0, 1]]] # Broadcast 3-d array to 2-d
         
     sa[[0, 1], 0] = [[0, 1]] # Reduce dimensions
+    
+    # Check closed and open slices
+    sa = SparseArray.from_shape([5, 5])
+    sa[0:3, :] = 1
+    arr = np.zeros([5, 5])
+    arr[0:3, :] = 1
+    assert (sa == arr).all()
 
 def test_sparse_array_boolean_indexing():
     for dtype in (float, bool):
diff --git a/thermosteam/base/sparse.py b/thermosteam/base/sparse.py
index 51940c11..a1ecf443 100644
--- a/thermosteam/base/sparse.py
+++ b/thermosteam/base/sparse.py
@@ -820,7 +820,7 @@ def __setitem__(self, index, value):
                     rows = [rows[i] for i in default_range(m, len(rows))]
                 if n.__class__ is slice:
                     if n == open_slice:
-                        self[:] = value
+                        for i in rows: i[:] = value
                         return
                     else:
                         n = default_range(n, self.vector_size)