diff --git a/python/outlines_core/fsm/guide.py b/python/outlines_core/fsm/guide.py
index 26deb00e..ce92bfa3 100644
--- a/python/outlines_core/fsm/guide.py
+++ b/python/outlines_core/fsm/guide.py
@@ -9,7 +9,7 @@
     make_deterministic_fsm,
 )
 
-from .outlines_core_rs import PyVocabIndex
+from .outlines_core_rs import Index
 
 
 @dataclass(frozen=True)
@@ -109,7 +109,7 @@ def create_states_mapping(
     tokenizer,
     regex_parser: Callable[[str], interegular.Pattern] = interegular.parse_pattern,
     frozen_tokens: List[str] = [],
-) -> Tuple[PyVocabIndex, Set[int], Set[int]]:
+) -> Tuple[Index, Set[int], Set[int]]:
     """Create the variables related to the mapping between states and tokens from a regex string.
 
     The parameters of the function are used for caching purpose.
@@ -145,7 +145,7 @@ def create_states_mapping_from_fsm(
     fsm: interegular.fsm.FSM,
     tokenizer,
     frozen_tokens: List[str] = [],
-) -> Tuple[PyVocabIndex, Set[int], Set[int]]:
+) -> Tuple[Index, Set[int], Set[int]]:
     """Create the variables related to the mapping between states and tokens from an FSM.
 
     The parameters of the function are used for caching purpose.
diff --git a/python/outlines_core/fsm/outlines_core_rs.pyi b/python/outlines_core/fsm/outlines_core_rs.pyi
index 3dfe41e6..2cfedb68 100644
--- a/python/outlines_core/fsm/outlines_core_rs.pyi
+++ b/python/outlines_core/fsm/outlines_core_rs.pyi
@@ -87,7 +87,7 @@ class Vocabulary:
         """
         ...
 
-class PyVocabIndex:
+class Index:
     def get_allowed_tokens(self, state: int):
         """
         Return the next instruction for guided generation.
diff --git a/python/outlines_core/fsm/regex.py b/python/outlines_core/fsm/regex.py
index 3ab8af3d..af337e34 100644
--- a/python/outlines_core/fsm/regex.py
+++ b/python/outlines_core/fsm/regex.py
@@ -24,7 +24,7 @@
 
 from .outlines_core_rs import (  # noqa: F401
     FSMInfo,
-    PyVocabIndex,
+    Index,
     Vocabulary,
     _walk_fsm,
     create_fsm_index_end_to_end,
@@ -439,7 +439,7 @@ def create_fsm_index_tokenizer(
     fsm: BetterFSM,
     tokenizer,
     frozen_tokens: Optional[Iterable[str]] = None,
-) -> Tuple[PyVocabIndex, Set[int]]:
+) -> Tuple[Index, Set[int]]:
     """Construct an FMS index from a tokenizer.
 
     This uses the end-to-end approach of `create_fsm_index_end_to_end`.
@@ -470,7 +470,7 @@ def create_fsm_index_tokenizer(
     """
     tokens_to_token_ids, empty_token_ids = reduced_vocabulary(tokenizer)
 
-    states_to_token_subsets = PyVocabIndex(  # type: ignore
+    states_to_token_subsets = Index(  # type: ignore
         fsm.fsm_info,
         Vocabulary.from_dict(tokens_to_token_ids),
         tokenizer.eos_token_id,
diff --git a/src/python_bindings/mod.rs b/src/python_bindings/mod.rs
index f50f51dd..01ccc35b 100644
--- a/src/python_bindings/mod.rs
+++ b/src/python_bindings/mod.rs
@@ -46,7 +46,7 @@ impl FSMInfo {
 }
 
 #[pyclass]
-pub struct PyVocabIndex {
+pub struct Index {
     initial: u32,
     finals: HashSet<u32>,
     states_to_token_subsets: HashMap<u32, HashMap<u32, u32>>,
@@ -55,7 +55,7 @@ pub struct PyVocabIndex {
 }
 
 #[pymethods]
-impl PyVocabIndex {
+impl Index {
     #[new]
     fn new(
         fsm_info: &FSMInfo,
@@ -332,7 +332,7 @@ fn outlines_core_rs(m: &Bound<'_, PyModule>) -> PyResult<()> {
     m.add_function(wrap_pyfunction!(to_regex_py, m)?)?;
 
     m.add_class::<PyVocabulary>()?;
-    m.add_class::<PyVocabIndex>()?;
+    m.add_class::<Index>()?;
 
     Ok(())
 }