diff --git a/dm_env_rpc/v1/spec_manager_test.py b/dm_env_rpc/v1/spec_manager_test.py
index a8781ff..ea14b7c 100644
--- a/dm_env_rpc/v1/spec_manager_test.py
+++ b/dm_env_rpc/v1/spec_manager_test.py
@@ -102,13 +102,9 @@ def test_pack_wrong_shape_raises_error(self):
       self._spec_manager.pack({'foo': [1, 2]})
 
   def test_pack_wrong_dtype_raises_error(self):
-    with self.assertRaisesRegex(TypeError, 'int32'):
+    with self.assertRaises(ValueError):
       self._spec_manager.pack({'foo': 'hello'})
 
-  def test_pack_cast_float_to_int_raises_error(self):
-    with self.assertRaisesRegex(TypeError, 'int32'):
-      self._spec_manager.pack({'foo': [0.5, 1.0, 1]})
-
   def test_pack_cast_int_to_float_is_ok(self):
     packed = self._spec_manager.pack({'fuzz': [1, 2]})
     self.assertEqual([1.0, 2.0], packed[54].floats.array)
diff --git a/dm_env_rpc/v1/tensor_utils.py b/dm_env_rpc/v1/tensor_utils.py
index fc8bf39..02ee94e 100644
--- a/dm_env_rpc/v1/tensor_utils.py
+++ b/dm_env_rpc/v1/tensor_utils.py
@@ -322,7 +322,7 @@ def pack_tensor(
     value = value.astype(
         dtype=_DM_ENV_RPC_DTYPE_TO_NUMPY_DTYPE.get(dtype, dtype),
         copy=False,
-        casting='same_kind' if value.size else 'unsafe')
+        casting='unsafe')
 
   packed.shape[:] = value.shape
   packer = get_packer(value.dtype.type)
diff --git a/dm_env_rpc/v1/tensor_utils_test.py b/dm_env_rpc/v1/tensor_utils_test.py
index 63cf8bc..73c5a9f 100644
--- a/dm_env_rpc/v1/tensor_utils_test.py
+++ b/dm_env_rpc/v1/tensor_utils_test.py
@@ -168,7 +168,7 @@ def test_packed_rowmajor(self):
     np.testing.assert_array_equal([1, 2, 3, 4, 5, 6], tensor.int32s.array)
 
   def test_mixed_scalar_types_raises_exception(self):
-    with self.assertRaises(TypeError):
+    with self.assertRaises(ValueError):
       tensor_utils.pack_tensor(['hello!', 75], dtype=np.float32)
 
   def test_jagged_arrays_throw_exceptions(self):