diff --git a/vm/src/builtins/bytearray.rs b/vm/src/builtins/bytearray.rs
index 77c664946..2447c3f43 100644
--- a/vm/src/builtins/bytearray.rs
+++ b/vm/src/builtins/bytearray.rs
@@ -742,16 +742,14 @@ impl PyValue for PyByteArrayIterator {
 #[pyimpl(with(SlotIterator))]
 impl PyByteArrayIterator {
     #[pymethod(magic)]
-    fn length_hint(&self, vm: &VirtualMachine) -> PyResult {
+    fn length_hint(&self, vm: &VirtualMachine) -> PyObjectRef {
         self.internal.length_hint(
             || {
-                Ok(self
-                    .internal
+                self.internal
                     .obj
                     .read()
                     .payload::<PyByteArray>()
-                    .unwrap()
-                    .len())
+                    .map(|x| x.len())
             },
             vm,
         )
diff --git a/vm/src/builtins/bytes.rs b/vm/src/builtins/bytes.rs
index a94da0a17..616fb081c 100644
--- a/vm/src/builtins/bytes.rs
+++ b/vm/src/builtins/bytes.rs
@@ -594,9 +594,15 @@ impl PyValue for PyBytesIterator {
 #[pyimpl(with(SlotIterator))]
 impl PyBytesIterator {
     #[pymethod(magic)]
-    fn length_hint(&self, vm: &VirtualMachine) -> PyResult {
+    fn length_hint(&self, vm: &VirtualMachine) -> PyObjectRef {
         self.internal.length_hint(
-            || Ok(self.internal.obj.read().payload::<PyBytes>().unwrap().len()),
+            || {
+                self.internal
+                    .obj
+                    .read()
+                    .payload::<PyBytes>()
+                    .map(|x| x.len())
+            },
             vm,
         )
     }
diff --git a/vm/src/builtins/iter.rs b/vm/src/builtins/iter.rs
index 3a578106f..54065926f 100644
--- a/vm/src/builtins/iter.rs
+++ b/vm/src/builtins/iter.rs
@@ -79,18 +79,21 @@ impl PositionIterInternal {
         }
     }
 
-    pub fn length_hint<F>(&self, f: F, vm: &VirtualMachine) -> PyResult
+    pub fn length_hint<F>(&self, f: F, vm: &VirtualMachine) -> PyObjectRef
     where
-        F: FnOnce() -> PyResult<usize>,
+        F: FnOnce() -> Option<usize>,
     {
         let len = if self.is_active(vm) {
             let pos = self.position.load();
-            let obj_len = f()?;
-            obj_len.saturating_sub(pos)
+            if let Some(obj_len) = f() {
+                obj_len.saturating_sub(pos)
+            } else {
+                return vm.ctx.not_implemented();
+            }
         } else {
             0
         };
-        Ok(PyInt::from(len).into_object(vm))
+        PyInt::from(len).into_object(vm)
     }
 }
 
@@ -127,11 +130,10 @@ impl PySequenceIterator {
     }
 
     #[pymethod(magic)]
-    fn length_hint(&self, vm: &VirtualMachine) -> PyResult {
+    fn length_hint(&self, vm: &VirtualMachine) -> PyObjectRef {
         self.internal.length_hint(
             || {
-                vm.obj_len(&self.internal.obj.read())
-                    .map_err(|_| vm.new_not_implemented_error("".to_owned()))
+                vm.obj_len(&self.internal.obj.read()).ok()
             },
             vm,
         )
diff --git a/vm/src/builtins/tuple.rs b/vm/src/builtins/tuple.rs
index 160f01d47..3ee0edce4 100644
--- a/vm/src/builtins/tuple.rs
+++ b/vm/src/builtins/tuple.rs
@@ -331,9 +331,9 @@ impl PyValue for PyTupleIterator {
 #[pyimpl(with(SlotIterator))]
 impl PyTupleIterator {
     #[pymethod(magic)]
-    fn length_hint(&self, vm: &VirtualMachine) -> PyResult {
+    fn length_hint(&self, vm: &VirtualMachine) -> PyObjectRef {
         self.internal.length_hint(
-            || Ok(self.internal.obj.read().payload::<PyTuple>().unwrap().len()),
+            || self.internal.obj.read().payload::<PyTuple>().map(|x| x.len()),
             vm,
         )
     }