diff --git a/compiler/gen_llvm/src/llvm/build.rs b/compiler/gen_llvm/src/llvm/build.rs
index 0b102b723f..ebed84e80d 100644
--- a/compiler/gen_llvm/src/llvm/build.rs
+++ b/compiler/gen_llvm/src/llvm/build.rs
@@ -4648,27 +4648,6 @@ fn run_low_level<'a, 'ctx, 'env>(
                 wrapper_struct,
             )
         }
-        ListSetInPlace => {
-            let (list, list_layout) = load_symbol_and_layout(scope, &args[0]);
-            let (index, _) = load_symbol_and_layout(scope, &args[1]);
-            let (element, _) = load_symbol_and_layout(scope, &args[2]);
-
-            match list_layout {
-                Layout::Builtin(Builtin::EmptyList) => {
-                    // no elements, so nothing to remove
-                    empty_list(env)
-                }
-                Layout::Builtin(Builtin::List(element_layout)) => list_set(
-                    env,
-                    layout_ids,
-                    list,
-                    index.into_int_value(),
-                    element,
-                    element_layout,
-                ),
-                _ => unreachable!("invalid dict layout"),
-            }
-        }
         ListSet => {
             let (list, list_layout) = load_symbol_and_layout(scope, &args[0]);
             let (index, _) = load_symbol_and_layout(scope, &args[1]);
diff --git a/compiler/module/src/low_level.rs b/compiler/module/src/low_level.rs
index d20c57a420..98a1f48cf8 100644
--- a/compiler/module/src/low_level.rs
+++ b/compiler/module/src/low_level.rs
@@ -18,7 +18,6 @@ pub enum LowLevel {
     ListLen,
     ListGetUnsafe,
     ListSet,
-    ListSetInPlace,
     ListSingle,
     ListRepeat,
     ListReverse,
@@ -125,7 +124,6 @@ impl LowLevel {
             | ListLen
             | ListGetUnsafe
             | ListSet
-            | ListSetInPlace
             | ListDrop
             | ListSingle
             | ListRepeat
diff --git a/compiler/mono/src/borrow.rs b/compiler/mono/src/borrow.rs
index 9df746da8f..d63f4dad5e 100644
--- a/compiler/mono/src/borrow.rs
+++ b/compiler/mono/src/borrow.rs
@@ -760,7 +760,6 @@ pub fn lowlevel_borrow_signature(arena: &Bump, op: LowLevel) -> &[bool] {
     match op {
         ListLen | StrIsEmpty | StrCountGraphemes => arena.alloc_slice_copy(&[borrowed]),
         ListSet => arena.alloc_slice_copy(&[owned, irrelevant, irrelevant]),
-        ListSetInPlace => arena.alloc_slice_copy(&[owned, irrelevant, irrelevant]),
         ListGetUnsafe => arena.alloc_slice_copy(&[borrowed, irrelevant]),
         ListConcat => arena.alloc_slice_copy(&[owned, owned]),
         StrConcat => arena.alloc_slice_copy(&[owned, borrowed]),