diff --git a/Cargo.toml b/Cargo.toml
index ec1a1de..d9d22f5 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -10,13 +10,13 @@ name = "tantivy"
 crate-type = ["cdylib"]
 
 [dependencies]
-chrono = "0.4.10"
+chrono = "0.4.11"
 tantivy = "0.12.0"
-itertools = "0.8.2"
+itertools = "0.9.0"
 futures = "0.3.4"
 
 [dependencies.pyo3]
-version = "0.8.5"
+version = "0.9.2"
 features = ["extension-module"]
 
 [package.metadata.maturin]
diff --git a/rust-toolchain b/rust-toolchain
index ac6e456..1b77fcf 100644
--- a/rust-toolchain
+++ b/rust-toolchain
@@ -1 +1 @@
-nightly-2020-01-03
+nightly-2020-04-18
diff --git a/src/document.rs b/src/document.rs
index a8d2e8e..2818bf3 100644
--- a/src/document.rs
+++ b/src/document.rs
@@ -127,7 +127,7 @@ pub(crate) fn extract_value(any: &PyAny) -> PyResult<Value> {
     if let Ok(num) = any.extract::<f64>() {
         return Ok(Value::F64(num));
     }
-    if let Ok(py_datetime) = any.downcast_ref::<PyDateTime>() {
+    if let Ok(py_datetime) = any.downcast::<PyDateTime>() {
         let datetime = Utc
             .ymd(
                 py_datetime.get_year(),
@@ -142,14 +142,14 @@ pub(crate) fn extract_value(any: &PyAny) -> PyResult<Value> {
             );
         return Ok(Value::Date(datetime));
     }
-    if let Ok(facet) = any.downcast_ref::<Facet>() {
+    if let Ok(facet) = any.extract::<Facet>() {
         return Ok(Value::Facet(facet.inner.clone()));
     }
     Err(to_pyerr(format!("Value unsupported {:?}", any)))
 }
 
 fn extract_value_single_or_list(any: &PyAny) -> PyResult<Vec<Value>> {
-    if let Ok(values) = any.downcast_ref::<PyList>() {
+    if let Ok(values) = any.downcast::<PyList>() {
         values.iter().map(extract_value).collect()
     } else {
         Ok(vec![extract_value(any)?])
@@ -160,20 +160,19 @@ fn extract_value_single_or_list(any: &PyAny) -> PyResult<Vec<Value>> {
 impl Document {
     #[new]
     #[args(kwargs = "**")]
-    fn new(obj: &PyRawObject, kwargs: Option<&PyDict>) -> PyResult<()> {
+    fn new(kwargs: Option<&PyDict>) -> PyResult<Self> {
         let mut document = Document::default();
         if let Some(field_dict) = kwargs {
             document.extend(field_dict)?;
         }
-        obj.init(document);
-        Ok(())
+        Ok(document)
     }
 
     fn extend(&mut self, py_dict: &PyDict) -> PyResult<()> {
         let mut field_values: BTreeMap<String, Vec<tv::schema::Value>> =
             BTreeMap::new();
         for key_value_any in py_dict.items() {
-            if let Ok(key_value) = key_value_any.downcast_ref::<PyTuple>() {
+            if let Ok(key_value) = key_value_any.downcast::<PyTuple>() {
                 if key_value.len() != 2 {
                     continue;
                 }
@@ -192,7 +191,7 @@ impl Document {
         let mut field_values: BTreeMap<String, Vec<tv::schema::Value>> =
             BTreeMap::new();
         for key_value_any in py_dict.items() {
-            if let Ok(key_value) = key_value_any.downcast_ref::<PyTuple>() {
+            if let Ok(key_value) = key_value_any.downcast::<PyTuple>() {
                 if key_value.len() != 2 {
                     continue;
                 }
diff --git a/src/facet.rs b/src/facet.rs
index 1686a7c..3216b30 100644
--- a/src/facet.rs
+++ b/src/facet.rs
@@ -13,6 +13,7 @@ use tantivy::schema;
 /// ancestor of its facet. In the example above, /electronics/tv_and_video/
 /// and /electronics.
 #[pyclass]
+#[derive(Clone)]
 pub(crate) struct Facet {
     pub(crate) inner: schema::Facet,
 }
diff --git a/src/index.rs b/src/index.rs
index c7760bc..551e646 100644
--- a/src/index.rs
+++ b/src/index.rs
@@ -165,11 +165,10 @@ impl Index {
     #[new]
     #[args(reuse = true)]
     fn new(
-        obj: &PyRawObject,
         schema: &Schema,
         path: Option<&str>,
         reuse: bool,
-    ) -> PyResult<()> {
+    ) -> PyResult<Self> {
         let index = match path {
             Some(p) => {
                 let directory = MmapDirectory::open(p).map_err(to_pyerr)?;
@@ -184,8 +183,7 @@ impl Index {
         };
 
         let reader = index.reader().map_err(to_pyerr)?;
-        obj.init(Index { index, reader });
-        Ok(())
+        Ok(Index { index, reader })
     }
 
     /// Create a `IndexWriter` for the index.
diff --git a/src/schemabuilder.rs b/src/schemabuilder.rs
index 95233c7..6fd7128 100644
--- a/src/schemabuilder.rs
+++ b/src/schemabuilder.rs
@@ -35,10 +35,10 @@ const RECORD: &str = "position";
 #[pymethods]
 impl SchemaBuilder {
     #[new]
-    fn new(obj: &PyRawObject) {
-        obj.init(SchemaBuilder {
+    fn new() -> Self {
+        SchemaBuilder {
             builder: Arc::new(From::from(Some(schema::Schema::builder()))),
-        });
+        }
     }
 
     /// Add a new text field to the schema.