diff --git a/lindi/LindiH5pyFile/LindiH5pyAttributes.py b/lindi/LindiH5pyFile/LindiH5pyAttributes.py
index 34444ed..5dd7715 100644
--- a/lindi/LindiH5pyFile/LindiH5pyAttributes.py
+++ b/lindi/LindiH5pyFile/LindiH5pyAttributes.py
@@ -2,7 +2,7 @@
 from .LindiH5pyReference import LindiH5pyReference
 from ..conversion.attr_conversion import zarr_to_h5_attr
 from ..conversion.nan_inf_ninf import decode_nan_inf_ninf
-from .write.LindiH5pyAttributesWrite import LindiH5pyAttributesWrite
+from .writers.LindiH5pyAttributesWriter import LindiH5pyAttributesWriter
 
 _special_attribute_keys = [
     "_SCALAR",
@@ -19,7 +19,10 @@ def __init__(self, attrs, attrs_type: Literal["h5py", "zarr"], readonly: bool):
         self._attrs_type = attrs_type
         self._readonly = readonly
 
-        self._write = LindiH5pyAttributesWrite(self)
+        if self._readonly:
+            self._writer = None
+        else:
+            self._writer = LindiH5pyAttributesWriter(self)
 
     def get(self, key, default=None):
         if self._attrs_type == "h5py":
@@ -61,7 +64,10 @@ def __getitem__(self, key):
             raise ValueError(f"Unknown attrs_type: {self._attrs_type}")
 
     def __setitem__(self, key, value):
-        self._write.__setitem__(key, value)
+        if self._readonly:
+            raise ValueError("Cannot set items on read-only object")
+        assert self._writer is not None
+        self._writer.__setitem__(key, value)
 
     def __delitem__(self, key):
         raise KeyError("Cannot delete attributes on read-only object")
diff --git a/lindi/LindiH5pyFile/LindiH5pyDataset.py b/lindi/LindiH5pyFile/LindiH5pyDataset.py
index 049215d..5973739 100644
--- a/lindi/LindiH5pyFile/LindiH5pyDataset.py
+++ b/lindi/LindiH5pyFile/LindiH5pyDataset.py
@@ -30,6 +30,7 @@ class LindiH5pyDataset(h5py.Dataset):
     def __init__(self, _dataset_object: Union[h5py.Dataset, zarr.Array], _file: "LindiH5pyFile"):
         self._dataset_object = _dataset_object
         self._file = _file
+        self._readonly = _file.mode not in ['r+']
 
         # See if we have the _COMPOUND_DTYPE attribute, which signifies that
         # this is a compound dtype
@@ -62,8 +63,12 @@ def __init__(self, _dataset_object: Union[h5py.Dataset, zarr.Array], _file: "Lin
             self._is_scalar = self._dataset_object.ndim == 0
 
         # The self._write object handles all the writing operations
-        from .write.LindiH5pyDatasetWrite import LindiH5pyDatasetWrite  # avoid circular import
-        self._write = LindiH5pyDatasetWrite(self)
+        from .writers.LindiH5pyDatasetWriter import LindiH5pyDatasetWriter  # avoid circular import
+
+        if self._readonly:
+            self._writer = None
+        else:
+            self._writer = LindiH5pyDatasetWriter(self)
 
     @property
     def id(self):
@@ -224,14 +229,18 @@ def _get_external_hdf5_client(self, url: str) -> h5py.File:
 
     @property
     def ref(self):
-        return self._write.ref
+        if self._readonly:
+            raise ValueError("Cannot get ref on read-only object")
+        assert self._writer is not None
+        return self._writer.ref
 
     ##############################
     # Write
     def __setitem__(self, args, val):
-        if self._file._mode not in ['r+']:
-            raise Exception('Cannot set item on dataset in read-only mode.')
-        self._write.__setitem__(args, val)
+        if self._readonly:
+            raise ValueError("Cannot set items on read-only object")
+        assert self._writer is not None
+        self._writer.__setitem__(args, val)
 
 
 class LindiH5pyDatasetCompoundFieldSelection:
diff --git a/lindi/LindiH5pyFile/LindiH5pyGroup.py b/lindi/LindiH5pyFile/LindiH5pyGroup.py
index db8b755..89d303f 100644
--- a/lindi/LindiH5pyFile/LindiH5pyGroup.py
+++ b/lindi/LindiH5pyFile/LindiH5pyGroup.py
@@ -20,10 +20,14 @@ class LindiH5pyGroup(h5py.Group):
     def __init__(self, _group_object: Union[h5py.Group, zarr.Group], _file: "LindiH5pyFile"):
         self._group_object = _group_object
         self._file = _file
+        self._readonly = _file.mode not in ['r+']
 
         # The self._write object handles all the writing operations
-        from .write.LindiH5pyGroupWrite import LindiH5pyGroupWrite  # avoid circular import
-        self._write = LindiH5pyGroupWrite(self)
+        from .writers.LindiH5pyGroupWriter import LindiH5pyGroupWriter  # avoid circular import
+        if self._readonly:
+            self._writer = None
+        else:
+            self._writer = LindiH5pyGroupWriter(self)
 
     def __getitem__(self, name):
         if isinstance(self._group_object, h5py.Group):
@@ -154,31 +158,39 @@ def attrs(self):  # type: ignore
 
     @property
     def ref(self):
-        return self._write.ref
+        if self._readonly:
+            raise ValueError("Cannot get ref on read-only object")
+        assert self._writer is not None
+        return self._writer.ref
 
     ##############################
     # write
     def create_group(self, name, track_order=None):
-        if self._file._mode not in ['r+']:
+        if self._readonly:
             raise Exception('Cannot create group in read-only mode')
-        return self._write.create_group(name, track_order=track_order)
+        assert self._writer is not None
+        return self._writer.create_group(name, track_order=track_order)
 
     def require_group(self, name):
-        if self._file._mode not in ['r+']:
+        if self._readonly:
             raise Exception('Cannot require group in read-only mode')
-        return self._write.require_group(name)
+        assert self._writer is not None
+        return self._writer.require_group(name)
 
     def create_dataset(self, name, shape=None, dtype=None, data=None, **kwds):
-        if self._file._mode not in ['r+']:
+        if self._readonly:
             raise Exception('Cannot create dataset in read-only mode')
-        return self._write.create_dataset(name, shape=shape, dtype=dtype, data=data, **kwds)
+        assert self._writer is not None
+        return self._writer.create_dataset(name, shape=shape, dtype=dtype, data=data, **kwds)
 
     def __setitem__(self, name, obj):
-        if self._file._mode not in ['r+']:
+        if self._readonly:
             raise Exception('Cannot set item in read-only mode')
-        return self._write.__setitem__(name, obj)
+        assert self._writer is not None
+        return self._writer.__setitem__(name, obj)
 
     def __delitem__(self, name):
-        if self._file._mode not in ['r+']:
+        if self._readonly:
             raise Exception('Cannot delete item in read-only mode')
-        return self._write.__delitem__(name)
+        assert self._writer is not None
+        return self._writer.__delitem__(name)
diff --git a/lindi/LindiH5pyFile/write/LindiH5pyAttributesWrite.py b/lindi/LindiH5pyFile/writers/LindiH5pyAttributesWriter.py
similarity index 95%
rename from lindi/LindiH5pyFile/write/LindiH5pyAttributesWrite.py
rename to lindi/LindiH5pyFile/writers/LindiH5pyAttributesWriter.py
index 6d77886..d2908ab 100644
--- a/lindi/LindiH5pyFile/write/LindiH5pyAttributesWrite.py
+++ b/lindi/LindiH5pyFile/writers/LindiH5pyAttributesWriter.py
@@ -4,7 +4,7 @@
     from ..LindiH5pyAttributes import LindiH5pyAttributes  # pragma: no cover
 
 
-class LindiH5pyAttributesWrite:
+class LindiH5pyAttributesWriter:
     def __init__(self, p: 'LindiH5pyAttributes'):
         self.p = p
 
diff --git a/lindi/LindiH5pyFile/write/LindiH5pyDatasetWrite.py b/lindi/LindiH5pyFile/writers/LindiH5pyDatasetWriter.py
similarity index 98%
rename from lindi/LindiH5pyFile/write/LindiH5pyDatasetWrite.py
rename to lindi/LindiH5pyFile/writers/LindiH5pyDatasetWriter.py
index 5d7fd0e..c455e79 100644
--- a/lindi/LindiH5pyFile/write/LindiH5pyDatasetWrite.py
+++ b/lindi/LindiH5pyFile/writers/LindiH5pyDatasetWriter.py
@@ -11,7 +11,7 @@
     from ..LindiH5pyDataset import LindiH5pyDataset  # pragma: no cover
 
 
-class LindiH5pyDatasetWrite:
+class LindiH5pyDatasetWriter:
     def __init__(self, p: 'LindiH5pyDataset'):
         self.p = p
 
diff --git a/lindi/LindiH5pyFile/write/LindiH5pyGroupWrite.py b/lindi/LindiH5pyFile/writers/LindiH5pyGroupWriter.py
similarity index 99%
rename from lindi/LindiH5pyFile/write/LindiH5pyGroupWrite.py
rename to lindi/LindiH5pyFile/writers/LindiH5pyGroupWriter.py
index 5526aa9..5bfa58e 100644
--- a/lindi/LindiH5pyFile/write/LindiH5pyGroupWrite.py
+++ b/lindi/LindiH5pyFile/writers/LindiH5pyGroupWriter.py
@@ -12,7 +12,7 @@
 from ...conversion.create_zarr_dataset_from_h5_data import create_zarr_dataset_from_h5_data
 
 
-class LindiH5pyGroupWrite:
+class LindiH5pyGroupWriter:
     def __init__(self, p: 'LindiH5pyGroup'):
         self.p = p
 
diff --git a/lindi/LindiH5pyFile/write/__init__.py b/lindi/LindiH5pyFile/writers/__init__.py
similarity index 100%
rename from lindi/LindiH5pyFile/write/__init__.py
rename to lindi/LindiH5pyFile/writers/__init__.py