diff --git a/mnists/__init__.py b/mnists/__init__.py
index f43bc3e..9920bd3 100644
--- a/mnists/__init__.py
+++ b/mnists/__init__.py
@@ -218,10 +218,8 @@ def prepare(dataset="mnist", return_floats=True, return_onehot=True,
         test_images_data = test_images_data.transpose(0,1,3,2)
 
     if return_floats:  # TODO: better name.
-        train_images_data = train_images_data.astype(np.float32) / np.float32(255)
-        test_images_data = test_images_data.astype(np.float32) / np.float32(255)
-        assert train_images_data.dtype == 'float32'
-        assert test_images_data.dtype == 'float32'
+        train_images_data = train_images_data.astype(np.float32) / 255
+        test_images_data = test_images_data.astype(np.float32) / 255
 
     # emnist_letters uses labels indexed from 1 instead of the usual 0.
     # the onehot function assumes labels are contiguous from 0.