diff --git a/python/src/array.cpp b/python/src/array.cpp
index 5ce09dd90..6ca0ab0ca 100644
--- a/python/src/array.cpp
+++ b/python/src/array.cpp
@@ -208,6 +208,7 @@ using array_init_type = std::variant<
     std::complex<float>,
     py::list,
     py::tuple,
+    array,
     py::array,
     py::buffer,
     py::object>;
@@ -410,8 +411,9 @@ std::optional<std::string> buffer_format(const array& a) {
     }
     case bfloat16:
       // not supported by python buffer protocol or numpy.
-      // musst be null according to
+      // must be null according to
       // https://docs.python.org/3.10/c-api/buffer.html#c.PyBUF_FORMAT
+      // which implies 'B'.
       return {};
     case complex64:
       return pybind11::format_descriptor<std::complex<float>>::format();
@@ -449,6 +451,8 @@ array create_array(array_init_type v, std::optional<Dtype> t) {
     return array_from_list(*pv, t);
   } else if (auto pv = std::get_if<py::tuple>(&v); pv) {
     return array_from_list(*pv, t);
+  } else if (auto pv = std::get_if<array>(&v); pv) {
+    return astype(*pv, t.value_or((*pv).dtype()));
   } else if (auto pv = std::get_if<py::array>(&v); pv) {
     return np_array_to_mlx(*pv, t);
   } else if (auto pv = std::get_if<py::buffer>(&v); pv) {
@@ -528,7 +532,8 @@ void init_array(py::module_& m) {
         return pybind11::buffer_info(
             a.data<void>(),
             a.itemsize(),
-            buffer_format(a).value_or(nullptr),
+            buffer_format(a).value_or("B"), // we use "B" because pybind uses a
+                                            // std::string which can't be null
             a.ndim(),
             a.shape(),
             buffer_strides(a));
diff --git a/python/tests/mlx_tests.py b/python/tests/mlx_tests.py
index 9e8ed772e..8cccc61ec 100644
--- a/python/tests/mlx_tests.py
+++ b/python/tests/mlx_tests.py
@@ -52,10 +52,21 @@ class MLXTestCase(unittest.TestCase):
         atol=1e-2,
         rtol=1e-2,
     ):
-        assert tuple(mx_res.shape) == tuple(
-            expected.shape
-        ), f"shape mismatch expected={expected.shape} got={mx_res.shape}"
-        assert (
-            mx_res.dtype == expected.dtype
-        ), f"dtype mismatch expected={expected.dtype} got={mx_res.dtype}"
-        np.testing.assert_allclose(mx_res, expected, rtol=rtol, atol=atol)
+        self.assertEqual(
+            tuple(mx_res.shape),
+            tuple(expected.shape),
+            msg=f"shape mismatch expected={expected.shape} got={mx_res.shape}",
+        )
+        self.assertEqual(
+            mx_res.dtype,
+            expected.dtype,
+            msg=f"dtype mismatch expected={expected.dtype} got={mx_res.dtype}",
+        )
+        if not isinstance(mx_res, mx.array) and not isinstance(expected, mx.array):
+            np.testing.assert_allclose(mx_res, expected, rtol=rtol, atol=atol)
+        elif not isinstance(mx_res, mx.array):
+            mx_res = mx.array(mx_res)
+            self.assertTrue(mx.allclose(mx_res, expected, rtol=rtol, atol=atol))
+        elif not isinstance(expected, mx.array):
+            expected = mx.array(expected)
+            self.assertTrue(mx.allclose(mx_res, expected, rtol=rtol, atol=atol))
diff --git a/python/tests/test_array.py b/python/tests/test_array.py
index eee570920..44775a11a 100644
--- a/python/tests/test_array.py
+++ b/python/tests/test_array.py
@@ -1170,7 +1170,6 @@ class TestArray(mlx_tests.MLXTestCase):
                     f(a_np),
                     atol=0,
                     rtol=0,
-                    msg=f"{mlx_dtype}{np_dtype}",
                 )
 
         # extra test for bfloat16, which is not numpy convertible
@@ -1178,7 +1177,7 @@ class TestArray(mlx_tests.MLXTestCase):
         mv_mx = memoryview(a_mx)
         self.assertEqual(mv_mx.strides, (8, 2))
         self.assertEqual(mv_mx.shape, (3, 4))
-        self.assertEqual(mv_mx.format, "")
+        self.assertEqual(mv_mx.format, "B")
         with self.assertRaises(RuntimeError) as cm:
             np.array(a_mx)
         e = cm.exception
@@ -1265,7 +1264,6 @@ class TestArray(mlx_tests.MLXTestCase):
                     f(a_tf),
                     atol=0,
                     rtol=0,
-                    msg=f"{mlx_dtype}{tf_dtype}",
                 )