diff --git a/tests/test_upper.py b/tests/test_upper.py
new file mode 100644
index 0000000..46e5d82
--- /dev/null
+++ b/tests/test_upper.py
@@ -0,0 +1,48 @@
+import pytest
+
+import arrayfire_wrapper.dtypes as dtypes
+from arrayfire_wrapper.lib.create_and_modify_array.create_array.constant import constant
+from arrayfire_wrapper.lib.create_and_modify_array.create_array.diag import diag_extract
+from arrayfire_wrapper.lib.create_and_modify_array.create_array.upper import upper
+from arrayfire_wrapper.lib.create_and_modify_array.manage_array import get_scalar
+
+
+@pytest.mark.parametrize(
+    "shape",
+    [
+        (3, 3),
+        (3, 3, 3),
+        (3, 3, 3, 3),
+    ],
+)
+def test_diag_is_unit(shape: tuple) -> None:
+    """Test if when is_unit_diag in lower returns an array with a unit diagonal"""
+    dtype = dtypes.s64
+    constant_array = constant(3, shape, dtype)
+
+    lower_array = upper(constant_array, True)
+    diagonal = diag_extract(lower_array, 0)
+    diagonal_value = get_scalar(diagonal, dtype)
+
+    assert diagonal_value == 1
+
+
+@pytest.mark.parametrize(
+    "shape",
+    [
+        (3, 3),
+        (3, 3, 3),
+        (3, 3, 3, 3),
+    ],
+)
+def test_is_original(shape: tuple) -> None:
+    """Test if is_original keeps the diagonal the same as the original array"""
+    dtype = dtypes.s64
+    constant_array = constant(3, shape, dtype)
+    original_value = get_scalar(constant_array, dtype)
+
+    lower_array = upper(constant_array, False)
+    diagonal = diag_extract(lower_array, 0)
+    diagonal_value = get_scalar(diagonal, dtype)
+
+    assert original_value == diagonal_value