diff --git a/src/gadgets/insert.rs b/src/gadgets/insert.rs
index 1f69cb24..6632eae7 100644
--- a/src/gadgets/insert.rs
+++ b/src/gadgets/insert.rs
@@ -37,8 +37,7 @@ impl<F: Extendable<D>, const D: usize> CircuitBuilder<F, D> {
         self.sub(one, not_equal)
     }
 
-    /// Inserts a `Target` in a vector at a non-deterministic index. This is done by rotating to the
-    /// left, inserting at 0 and then rotating to the right.
+    /// Inserts a `Target` in a vector at a non-deterministic index.
     /// Note: `index` is not range-checked.
     pub fn insert(
         &mut self,
@@ -49,9 +48,8 @@ impl<F: Extendable<D>, const D: usize> CircuitBuilder<F, D> {
         let mut already_inserted = self.zero();
         let mut new_list = Vec::new();
 
-        for i in 0..v.len() {
-            let one = self.one();
-
+        let one = self.one();
+        for i in 0..=v.len() {
             let cur_index = self.constant(F::from_canonical_usize(i));
             let insert_here = self.is_equal(cur_index, index);
 
@@ -63,11 +61,14 @@ impl<F: Extendable<D>, const D: usize> CircuitBuilder<F, D> {
             already_inserted = self.add(already_inserted, insert_here);
 
             let not_already_inserted = self.sub(one, already_inserted);
-            new_item = self.scalar_mul_add_extension(not_already_inserted, v[i], new_item);
+            if i < v.len() {
+                new_item = self.scalar_mul_add_extension(not_already_inserted, v[i], new_item);
+            }
 
             new_list.push(new_item);
         }
 
+
         new_list
     }
 }
@@ -106,6 +107,8 @@ mod tests {
             let inserted = real_insert(i, elem, &v);
             let purported_inserted = builder.insert(it, elem, v.clone());
 
+            assert_eq!(inserted.len(), purported_inserted.len());
+
             for (x, y) in inserted.into_iter().zip(purported_inserted) {
                 builder.route_extension(x, y);
             }