diff --git a/stdlib/src/array.rs b/stdlib/src/array.rs
index 3241e2444d..c002bed8e2 100644
--- a/stdlib/src/array.rs
+++ b/stdlib/src/array.rs
@@ -23,7 +23,7 @@ mod array {
                 BufferDescriptor, BufferMethods, BufferResizeGuard, PyBuffer, PyIterReturn,
                 PyMappingMethods,
             },
-            sequence::{SequenceExt, SequenceMutExt},
+            sequence::{OptionalRangeArgs, SequenceExt, SequenceMutExt},
             sliceable::{
                 SaturatedSlice, SequenceIndex, SequenceIndexOp, SliceableSequenceMutOp,
                 SliceableSequenceOp,
@@ -867,17 +867,10 @@ mod array {
         fn index(
             &self,
             x: PyObjectRef,
-            start: OptionalArg<PyObjectRef>,
-            stop: OptionalArg<PyObjectRef>,
+            range: OptionalRangeArgs,
             vm: &VirtualMachine,
         ) -> PyResult<usize> {
-            let len = self.len();
-            let saturate = |obj: PyObjectRef, len| -> PyResult<_> {
-                obj.try_into_value(vm)
-                    .map(|int: PyIntRef| int.as_bigint().saturated_at(len))
-            };
-            let start = start.map_or(Ok(0), |obj| saturate(obj, len))?;
-            let stop = stop.map_or(Ok(len), |obj| saturate(obj, len))?;
+            let (start, stop) = range.saturate(self.len(), vm)?;
             self.read().index(x, start, stop, vm)
         }
 
diff --git a/vm/src/builtins/list.rs b/vm/src/builtins/list.rs
index 19162b2f3f..0ab5eae69c 100644
--- a/vm/src/builtins/list.rs
+++ b/vm/src/builtins/list.rs
@@ -1,4 +1,4 @@
-use super::{PositionIterInternal, PyGenericAlias, PyIntRef, PyTupleRef, PyType, PyTypeRef};
+use super::{PositionIterInternal, PyGenericAlias, PyTupleRef, PyType, PyTypeRef};
 use crate::common::lock::{
     PyMappedRwLockReadGuard, PyMutex, PyRwLock, PyRwLockReadGuard, PyRwLockWriteGuard,
 };
@@ -9,8 +9,8 @@ use crate::{
     iter::PyExactSizeIterator,
     protocol::{PyIterReturn, PyMappingMethods, PySequence, PySequenceMethods},
     recursion::ReprGuard,
-    sequence::{MutObjectSequenceOp, SequenceExt, SequenceMutExt},
-    sliceable::{SequenceIndex, SequenceIndexOp, SliceableSequenceMutOp, SliceableSequenceOp},
+    sequence::{MutObjectSequenceOp, OptionalRangeArgs, SequenceExt, SequenceMutExt},
+    sliceable::{SequenceIndex, SliceableSequenceMutOp, SliceableSequenceOp},
     types::{
         AsMapping, AsSequence, Comparable, Constructor, Hashable, Initializer, IterNext,
         IterNextIterable, Iterable, PyComparisonOp, Unconstructible, Unhashable,
@@ -269,17 +269,10 @@ impl PyList {
     fn index(
         &self,
         needle: PyObjectRef,
-        start: OptionalArg<PyObjectRef>,
-        stop: OptionalArg<PyObjectRef>,
+        range: OptionalRangeArgs,
         vm: &VirtualMachine,
     ) -> PyResult<usize> {
-        let len = self.len();
-        let saturate = |obj: PyObjectRef, len| -> PyResult<_> {
-            obj.try_into_value(vm)
-                .map(|int: PyIntRef| int.as_bigint().saturated_at(len))
-        };
-        let start = start.map_or(Ok(0), |obj| saturate(obj, len))?;
-        let stop = stop.map_or(Ok(len), |obj| saturate(obj, len))?;
+        let (start, stop) = range.saturate(self.len(), vm)?;
         let index = self.mut_index_range(vm, &needle, start..stop)?;
         if let Some(index) = index.into() {
             Ok(index)
diff --git a/vm/src/builtins/tuple.rs b/vm/src/builtins/tuple.rs
index 8e3c11fef7..ce6d0cfbec 100644
--- a/vm/src/builtins/tuple.rs
+++ b/vm/src/builtins/tuple.rs
@@ -1,4 +1,4 @@
-use super::{PositionIterInternal, PyGenericAlias, PyIntRef, PyType, PyTypeRef};
+use super::{PositionIterInternal, PyGenericAlias, PyType, PyTypeRef};
 use crate::common::{hash::PyHash, lock::PyMutex};
 use crate::{
     class::PyClassImpl,
@@ -7,8 +7,7 @@ use crate::{
     iter::PyExactSizeIterator,
     protocol::{PyIterReturn, PyMappingMethods, PySequenceMethods},
     recursion::ReprGuard,
-    sequence::SequenceExt,
-    sliceable::SequenceIndexOp,
+    sequence::{OptionalRangeArgs, SequenceExt},
     sliceable::{SequenceIndex, SliceableSequenceOp},
     types::{
         AsMapping, AsSequence, Comparable, Constructor, Hashable, IterNext, IterNextIterable,
@@ -281,17 +280,10 @@ impl PyTuple {
     fn index(
         &self,
         needle: PyObjectRef,
-        start: OptionalArg<PyObjectRef>,
-        stop: OptionalArg<PyObjectRef>,
+        range: OptionalRangeArgs,
         vm: &VirtualMachine,
     ) -> PyResult<usize> {
-        let len = self.len();
-        let saturate = |obj: PyObjectRef, len| -> PyResult<_> {
-            obj.try_into_value(vm)
-                .map(|int: PyIntRef| int.as_bigint().saturated_at(len))
-        };
-        let start = start.map_or(Ok(0), |i| saturate(i, len))?;
-        let stop = stop.map_or(Ok(len), |i| saturate(i, len))?;
+        let (start, stop) = range.saturate(self.len(), vm)?;
         for (index, element) in self
             .elements
             .iter()
diff --git a/vm/src/sequence.rs b/vm/src/sequence.rs
index b7eb01964a..dc7a3b86ee 100644
--- a/vm/src/sequence.rs
+++ b/vm/src/sequence.rs
@@ -1,5 +1,7 @@
 use crate::{
-    function::{Either, PyComparisonValue},
+    builtins::PyIntRef,
+    function::{Either, OptionalArg, PyComparisonValue},
+    sliceable::SequenceIndexOp,
     types::{richcompare_wrapper, PyComparisonOp, RichCompareFunc},
     vm::VirtualMachine,
     AsObject, PyObject, PyObjectRef, PyResult,
@@ -225,3 +227,23 @@ impl<T: Clone> SequenceMutExt<T> for Vec<T> {
         self
     }
 }
+
+#[derive(FromArgs)]
+pub struct OptionalRangeArgs {
+    #[pyarg(positional, optional)]
+    start: OptionalArg<PyObjectRef>,
+    #[pyarg(positional, optional)]
+    stop: OptionalArg<PyObjectRef>,
+}
+
+impl OptionalRangeArgs {
+    pub fn saturate(self, len: usize, vm: &VirtualMachine) -> PyResult<(usize, usize)> {
+        let saturate = |obj: PyObjectRef| -> PyResult<_> {
+            obj.try_into_value(vm)
+                .map(|int: PyIntRef| int.as_bigint().saturated_at(len))
+        };
+        let start = self.start.map_or(Ok(0), saturate)?;
+        let stop = self.stop.map_or(Ok(len), saturate)?;
+        Ok((start, stop))
+    }
+}
diff --git a/vm/src/stdlib/collections.rs b/vm/src/stdlib/collections.rs
index 34cadd9b0c..a34c29afe4 100644
--- a/vm/src/stdlib/collections.rs
+++ b/vm/src/stdlib/collections.rs
@@ -5,14 +5,14 @@ mod _collections {
     use crate::{
         builtins::{
             IterStatus::{Active, Exhausted},
-            PositionIterInternal, PyGenericAlias, PyInt, PyIntRef, PyTypeRef,
+            PositionIterInternal, PyGenericAlias, PyInt, PyTypeRef,
         },
         common::lock::{PyMutex, PyRwLock, PyRwLockReadGuard, PyRwLockWriteGuard},
         function::{FuncArgs, KwArgs, OptionalArg, PyComparisonValue},
         iter::PyExactSizeIterator,
         protocol::{PyIterReturn, PySequenceMethods},
         recursion::ReprGuard,
-        sequence::MutObjectSequenceOp,
+        sequence::{MutObjectSequenceOp, OptionalRangeArgs},
         sliceable::SequenceIndexOp,
         types::{
             AsSequence, Comparable, Constructor, Hashable, Initializer, IterNext, IterNextIterable,
@@ -157,19 +157,12 @@ mod _collections {
         fn index(
             &self,
             needle: PyObjectRef,
-            start: OptionalArg<PyObjectRef>,
-            stop: OptionalArg<PyObjectRef>,
+            range: OptionalRangeArgs,
             vm: &VirtualMachine,
         ) -> PyResult<usize> {
             let start_state = self.state.load();
 
-            let len = self.len();
-            let saturate = |obj: PyObjectRef, len| -> PyResult<_> {
-                obj.try_into_value(vm)
-                    .map(|int: PyIntRef| int.as_bigint().saturated_at(len))
-            };
-            let start = start.map_or(Ok(0), |i| saturate(i, len))?;
-            let stop = stop.map_or(Ok(len), |i| saturate(i, len))?;
+            let (start, stop) = range.saturate(self.len(), vm)?;
             let index = self.mut_index_range(vm, &needle, start..stop)?;
             if start_state != self.state.load() {
                 Err(vm.new_runtime_error("deque mutated during iteration".to_owned()))