diff --git a/pyo3-arrow/src/array.rs b/pyo3-arrow/src/array.rs
index 42d385b..b0fc7e2 100644
--- a/pyo3-arrow/src/array.rs
+++ b/pyo3-arrow/src/array.rs
@@ -40,7 +40,7 @@ use crate::{PyDataType, PyField};
 /// In particular, storing a [FieldRef] is required to persist Arrow extension metadata through the
 /// C Data Interface.
 #[derive(Debug)]
-#[pyclass(module = "arro3.core._core", name = "Array", subclass)]
+#[pyclass(module = "arro3.core._core", name = "Array", subclass, frozen)]
 pub struct PyArray {
     array: ArrayRef,
     field: FieldRef,
diff --git a/pyo3-arrow/src/array_reader.rs b/pyo3-arrow/src/array_reader.rs
index f4f71e8..984d995 100644
--- a/pyo3-arrow/src/array_reader.rs
+++ b/pyo3-arrow/src/array_reader.rs
@@ -20,7 +20,7 @@ use crate::{PyArray, PyChunkedArray, PyField};
 /// A Python-facing Arrow array reader.
 ///
 /// This is a wrapper around a [ArrayReader].
-#[pyclass(module = "arro3.core._core", name = "ArrayReader", subclass)]
+#[pyclass(module = "arro3.core._core", name = "ArrayReader", subclass, frozen)]
 pub struct PyArrayReader(pub(crate) Mutex<Option<Box<dyn ArrayReader + Send>>>);
 
 impl PyArrayReader {
@@ -79,7 +79,7 @@ impl PyArrayReader {
 
     /// Export this to a Python `arro3.core.ArrayReader`.
     #[allow(clippy::wrong_self_convention)]
-    pub fn to_arro3<'py>(&'py mut self, py: Python<'py>) -> PyResult<Bound<'py, PyAny>> {
+    pub fn to_arro3<'py>(&'py self, py: Python<'py>) -> PyResult<Bound<'py, PyAny>> {
         let arro3_mod = py.import(intern!(py, "arro3.core"))?;
         arro3_mod.getattr(intern!(py, "ArrayReader"))?.call_method1(
             intern!(py, "from_arrow_pycapsule"),
@@ -89,7 +89,7 @@ impl PyArrayReader {
 
     /// Export this to a Python `nanoarrow.ArrayStream`.
     #[allow(clippy::wrong_self_convention)]
-    pub fn to_nanoarrow<'py>(&'py mut self, py: Python<'py>) -> PyResult<Bound<'py, PyAny>> {
+    pub fn to_nanoarrow<'py>(&'py self, py: Python<'py>) -> PyResult<Bound<'py, PyAny>> {
         to_nanoarrow_array_stream(py, &self.__arrow_c_stream__(py, None)?)
     }
 }
@@ -120,7 +120,7 @@ impl PyArrayReader {
 
     #[pyo3(signature = (requested_schema=None))]
     fn __arrow_c_stream__<'py>(
-        &'py mut self,
+        &'py self,
         py: Python<'py>,
         requested_schema: Option<Bound<'py, PyCapsule>>,
     ) -> PyArrowResult<Bound<'py, PyCapsule>> {
@@ -135,11 +135,11 @@ impl PyArrayReader {
 
     // Return self
     // https://stackoverflow.com/a/52056290
-    fn __iter__<'py>(&'py mut self, py: Python<'py>) -> PyResult<Bound<'py, PyAny>> {
+    fn __iter__<'py>(&'py self, py: Python<'py>) -> PyResult<Bound<'py, PyAny>> {
         self.to_arro3(py)
     }
 
-    fn __next__(&mut self) -> PyArrowResult<Arro3Array> {
+    fn __next__(&self) -> PyArrowResult<Arro3Array> {
         self.read_next_array()
     }
 
@@ -189,7 +189,7 @@ impl PyArrayReader {
         Ok(PyField::new(self.field_ref()?).into())
     }
 
-    fn read_all(&mut self) -> PyArrowResult<Arro3ChunkedArray> {
+    fn read_all(&self) -> PyArrowResult<Arro3ChunkedArray> {
         let stream = self
             .0
             .lock()
@@ -204,7 +204,7 @@ impl PyArrayReader {
         Ok(PyChunkedArray::try_new(arrays, field)?.into())
     }
 
-    fn read_next_array(&mut self) -> PyArrowResult<Arro3Array> {
+    fn read_next_array(&self) -> PyArrowResult<Arro3Array> {
         let mut inner = self.0.lock().unwrap();
         let stream = inner
             .as_mut()
diff --git a/pyo3-arrow/src/buffer.rs b/pyo3-arrow/src/buffer.rs
index 7e6a4f4..7069610 100644
--- a/pyo3-arrow/src/buffer.rs
+++ b/pyo3-arrow/src/buffer.rs
@@ -41,7 +41,7 @@ use crate::PyArray;
 /// The Python buffer protocol is implemented on this buffer to enable zero-copy data transfer of
 /// the core buffer into Python. This allows for zero-copy data sharing with numpy via
 /// `numpy.frombuffer`.
-#[pyclass(module = "arro3.core._core", name = "Buffer", subclass)]
+#[pyclass(module = "arro3.core._core", name = "Buffer", subclass, frozen)]
 pub struct PyArrowBuffer(Buffer);
 
 impl AsRef<Buffer> for PyArrowBuffer {
@@ -87,7 +87,7 @@ impl PyArrowBuffer {
     /// This is taken from opendal:
     /// https://github.com/apache/opendal/blob/d001321b0f9834bc1e2e7d463bcfdc3683e968c9/bindings/python/src/utils.rs#L51-L72
     unsafe fn __getbuffer__(
-        slf: PyRefMut<Self>,
+        slf: PyRef<Self>,
         view: *mut ffi::Py_buffer,
         flags: c_int,
     ) -> PyResult<()> {
diff --git a/pyo3-arrow/src/chunked.rs b/pyo3-arrow/src/chunked.rs
index 23e6a18..e501e43 100644
--- a/pyo3-arrow/src/chunked.rs
+++ b/pyo3-arrow/src/chunked.rs
@@ -25,7 +25,7 @@ use crate::{PyArray, PyDataType, PyField, PyScalar};
 ///
 /// This is a wrapper around a [FieldRef] and a `Vec` of [ArrayRef].
 #[derive(Debug)]
-#[pyclass(module = "arro3.core._core", name = "ChunkedArray", subclass)]
+#[pyclass(module = "arro3.core._core", name = "ChunkedArray", subclass, frozen)]
 pub struct PyChunkedArray {
     chunks: Vec<ArrayRef>,
     field: FieldRef,
diff --git a/pyo3-arrow/src/datatypes.rs b/pyo3-arrow/src/datatypes.rs
index f8ade06..84e1ee6 100644
--- a/pyo3-arrow/src/datatypes.rs
+++ b/pyo3-arrow/src/datatypes.rs
@@ -32,7 +32,7 @@ impl<'a> FromPyObject<'a> for PyTimeUnit {
 
 /// A Python-facing wrapper around [DataType].
 #[derive(PartialEq, Eq, Debug)]
-#[pyclass(module = "arro3.core._core", name = "DataType", subclass)]
+#[pyclass(module = "arro3.core._core", name = "DataType", subclass, frozen)]
 pub struct PyDataType(DataType);
 
 impl PyDataType {
diff --git a/pyo3-arrow/src/field.rs b/pyo3-arrow/src/field.rs
index f0e31ef..22a16e0 100644
--- a/pyo3-arrow/src/field.rs
+++ b/pyo3-arrow/src/field.rs
@@ -20,7 +20,7 @@ use crate::PyDataType;
 ///
 /// This is a wrapper around a [FieldRef].
 #[derive(Debug)]
-#[pyclass(module = "arro3.core._core", name = "Field", subclass)]
+#[pyclass(module = "arro3.core._core", name = "Field", subclass, frozen)]
 pub struct PyField(FieldRef);
 
 impl PyField {
diff --git a/pyo3-arrow/src/record_batch.rs b/pyo3-arrow/src/record_batch.rs
index d0f19d8..590f0ab 100644
--- a/pyo3-arrow/src/record_batch.rs
+++ b/pyo3-arrow/src/record_batch.rs
@@ -24,7 +24,7 @@ use crate::{PyArray, PyField, PySchema};
 /// A Python-facing Arrow record batch.
 ///
 /// This is a wrapper around a [RecordBatch].
-#[pyclass(module = "arro3.core._core", name = "RecordBatch", subclass)]
+#[pyclass(module = "arro3.core._core", name = "RecordBatch", subclass, frozen)]
 #[derive(Debug)]
 pub struct PyRecordBatch(RecordBatch);
 
diff --git a/pyo3-arrow/src/record_batch_reader.rs b/pyo3-arrow/src/record_batch_reader.rs
index 1963889..66e799b 100644
--- a/pyo3-arrow/src/record_batch_reader.rs
+++ b/pyo3-arrow/src/record_batch_reader.rs
@@ -22,7 +22,12 @@ use crate::{PyRecordBatch, PySchema, PyTable};
 /// A Python-facing Arrow record batch reader.
 ///
 /// This is a wrapper around a [RecordBatchReader].
-#[pyclass(module = "arro3.core._core", name = "RecordBatchReader", subclass)]
+#[pyclass(
+    module = "arro3.core._core",
+    name = "RecordBatchReader",
+    subclass,
+    frozen
+)]
 pub struct PyRecordBatchReader(pub(crate) Mutex<Option<Box<dyn RecordBatchReader + Send>>>);
 
 impl PyRecordBatchReader {
@@ -81,7 +86,7 @@ impl PyRecordBatchReader {
     }
 
     /// Export this to a Python `arro3.core.RecordBatchReader`.
-    pub fn to_arro3<'py>(&'py mut self, py: Python<'py>) -> PyResult<Bound<'py, PyAny>> {
+    pub fn to_arro3<'py>(&'py self, py: Python<'py>) -> PyResult<Bound<'py, PyAny>> {
         let arro3_mod = py.import(intern!(py, "arro3.core"))?;
         arro3_mod
             .getattr(intern!(py, "RecordBatchReader"))?
@@ -92,7 +97,7 @@ impl PyRecordBatchReader {
     }
 
     /// Export this to a Python `nanoarrow.ArrayStream`.
-    pub fn to_nanoarrow<'py>(&'py mut self, py: Python<'py>) -> PyResult<Bound<'py, PyAny>> {
+    pub fn to_nanoarrow<'py>(&'py self, py: Python<'py>) -> PyResult<Bound<'py, PyAny>> {
         to_nanoarrow_array_stream(py, &self.__arrow_c_stream__(py, None)?)
     }
 
@@ -155,7 +160,7 @@ impl PyRecordBatchReader {
 
     #[pyo3(signature = (requested_schema=None))]
     fn __arrow_c_stream__<'py>(
-        &'py mut self,
+        &'py self,
         py: Python<'py>,
         requested_schema: Option<Bound<'py, PyCapsule>>,
     ) -> PyArrowResult<Bound<'py, PyCapsule>> {
@@ -170,11 +175,11 @@ impl PyRecordBatchReader {
 
     // Return self
     // https://stackoverflow.com/a/52056290
-    fn __iter__<'py>(&'py mut self, py: Python<'py>) -> PyResult<Bound<'py, PyAny>> {
+    fn __iter__<'py>(&'py self, py: Python<'py>) -> PyResult<Bound<'py, PyAny>> {
         self.to_arro3(py)
     }
 
-    fn __next__(&mut self) -> PyArrowResult<Arro3RecordBatch> {
+    fn __next__(&self) -> PyArrowResult<Arro3RecordBatch> {
         self.read_next_batch()
     }
 
@@ -216,7 +221,7 @@ impl PyRecordBatchReader {
         self.0.lock().unwrap().is_none()
     }
 
-    fn read_all(&mut self) -> PyArrowResult<Arro3Table> {
+    fn read_all(&self) -> PyArrowResult<Arro3Table> {
         let stream = self
             .0
             .lock()
@@ -231,7 +236,7 @@ impl PyRecordBatchReader {
         Ok(PyTable::try_new(batches, schema)?.into())
     }
 
-    fn read_next_batch(&mut self) -> PyArrowResult<Arro3RecordBatch> {
+    fn read_next_batch(&self) -> PyArrowResult<Arro3RecordBatch> {
         let mut inner = self.0.lock().unwrap();
         let stream = inner
             .as_mut()
diff --git a/pyo3-arrow/src/scalar.rs b/pyo3-arrow/src/scalar.rs
index c81b4cb..b0220e0 100644
--- a/pyo3-arrow/src/scalar.rs
+++ b/pyo3-arrow/src/scalar.rs
@@ -19,7 +19,7 @@ use crate::{PyArray, PyField};
 
 /// A Python-facing Arrow scalar
 #[derive(Debug)]
-#[pyclass(module = "arro3.core._core", name = "Scalar", subclass)]
+#[pyclass(module = "arro3.core._core", name = "Scalar", subclass, frozen)]
 pub struct PyScalar {
     array: ArrayRef,
     field: FieldRef,
diff --git a/pyo3-arrow/src/schema.rs b/pyo3-arrow/src/schema.rs
index 96331a6..1552f56 100644
--- a/pyo3-arrow/src/schema.rs
+++ b/pyo3-arrow/src/schema.rs
@@ -20,7 +20,7 @@ use crate::{PyDataType, PyField, PyTable};
 ///
 /// This is a wrapper around a [SchemaRef].
 #[derive(Debug)]
-#[pyclass(module = "arro3.core._core", name = "Schema", subclass)]
+#[pyclass(module = "arro3.core._core", name = "Schema", subclass, frozen)]
 pub struct PySchema(SchemaRef);
 
 impl PySchema {
diff --git a/pyo3-arrow/src/table.rs b/pyo3-arrow/src/table.rs
index fbabf7e..5786a8d 100644
--- a/pyo3-arrow/src/table.rs
+++ b/pyo3-arrow/src/table.rs
@@ -32,7 +32,7 @@ use crate::{PyChunkedArray, PyField, PyRecordBatch, PyRecordBatchReader, PySchem
 /// A Python-facing Arrow table.
 ///
 /// This is a wrapper around a [SchemaRef] and a `Vec` of [RecordBatch].
-#[pyclass(module = "arro3.core._core", name = "Table", subclass)]
+#[pyclass(module = "arro3.core._core", name = "Table", subclass, frozen)]
 #[derive(Debug)]
 pub struct PyTable {
     batches: Vec<RecordBatch>,