diff --git a/src/hdmf/backends/hdf5/h5tools.py b/src/hdmf/backends/hdf5/h5tools.py
index e9156dc50..765ff6aa5 100644
--- a/src/hdmf/backends/hdf5/h5tools.py
+++ b/src/hdmf/backends/hdf5/h5tools.py
@@ -1609,22 +1609,25 @@ def set_dataio(cls, **kwargs):
     def generate_dataset_html(dataset):
         """Generates an html representation for a dataset for the HDF5IO class"""
 
-        # get info from hdf5 dataset
-        compressed_size = dataset.id.get_storage_size()
-        if hasattr(dataset, "nbytes"):  # TODO: Remove this after h5py minimal version is larger than 3.0
-            uncompressed_size = dataset.nbytes
-        else:
-            uncompressed_size = dataset.size * dataset.dtype.itemsize
-        compression_ratio = uncompressed_size / compressed_size if compressed_size != 0 else "undefined"
+        array_info_dict = get_basic_array_info(dataset)
+        if isinstance(dataset, h5py.Dataset):
 
-        hdf5_info_dict = {"Chunk shape": dataset.chunks,
-                          "Compression": dataset.compression,
-                          "Compression opts": dataset.compression_opts,
-                          "Compression ratio": compression_ratio}
+            # get info from hdf5 dataset
+            compressed_size = dataset.id.get_storage_size()
+            if hasattr(dataset, "nbytes"):  # TODO: Remove this after h5py minimal version is larger than 3.0
+                uncompressed_size = dataset.nbytes
+            else:
+                uncompressed_size = dataset.size * dataset.dtype.itemsize
+            compression_ratio = uncompressed_size / compressed_size if compressed_size != 0 else "undefined"
 
-        # get basic array info
-        array_info_dict = get_basic_array_info(dataset)
-        array_info_dict.update(hdf5_info_dict)
+            hdf5_info_dict = {
+                            "Chunk shape": dataset.chunks,
+                            "Compression": dataset.compression,
+                            "Compression opts": dataset.compression_opts,
+                            "Compression ratio": compression_ratio,
+                            }
+
+            array_info_dict.update(hdf5_info_dict)
 
         # generate html repr
         repr_html = generate_array_html_repr(array_info_dict, dataset, "HDF5 dataset")
diff --git a/src/hdmf/container.py b/src/hdmf/container.py
index 8f961936f..4ee24ec2d 100644
--- a/src/hdmf/container.py
+++ b/src/hdmf/container.py
@@ -754,7 +754,7 @@ def _generate_array_html(self, array, level):
         """Generates HTML for array data"""
 
         read_io = self.get_read_io()  # if the Container was read from file, get IO object
-        if read_io is not None:
+        if read_io is not None: # Note that sometimes numpy array have a read_io attribute
             repr_html = read_io.generate_dataset_html(array)
         else:
             array_info_dict = get_basic_array_info(array)