diff --git a/compiler/builtins/bitcode/src/list.zig b/compiler/builtins/bitcode/src/list.zig
index d83f888e22..6e6351a6e7 100644
--- a/compiler/builtins/bitcode/src/list.zig
+++ b/compiler/builtins/bitcode/src/list.zig
@@ -141,14 +141,14 @@ const Caller1 = fn (?[*]u8, ?[*]u8, ?[*]u8) callconv(.C) void;
 const Caller2 = fn (?[*]u8, ?[*]u8, ?[*]u8, ?[*]u8) callconv(.C) void;
 const Caller3 = fn (?[*]u8, ?[*]u8, ?[*]u8, ?[*]u8, ?[*]u8) callconv(.C) void;
 
-pub fn listReverse(list: RocList, alignment: u32, element_width: usize) callconv(.C) RocList {
+pub fn listReverse(list: RocList, alignment: u32, element_width: usize, update_mode: UpdateMode) callconv(.C) RocList {
     if (list.bytes) |source_ptr| {
         const size = list.len();
 
         var i: usize = 0;
         const end: usize = size - 1;
 
-        if (list.isUnique()) {
+        if (update_mode == .InPlace or list.isUnique()) {
 
             // Working from the front and back so
             // we only need to go ~(n / 2) iterations.
diff --git a/compiler/gen_llvm/src/llvm/build.rs b/compiler/gen_llvm/src/llvm/build.rs
index 4720653867..0694299329 100644
--- a/compiler/gen_llvm/src/llvm/build.rs
+++ b/compiler/gen_llvm/src/llvm/build.rs
@@ -4930,7 +4930,7 @@ fn run_low_level<'a, 'ctx, 'env>(
 
             let (list, list_layout) = load_symbol_and_layout(scope, &args[0]);
 
-            list_reverse(env, list, list_layout)
+            list_reverse(env, list, list_layout, update_mode)
         }
         ListConcat => {
             debug_assert_eq!(args.len(), 2);
diff --git a/compiler/gen_llvm/src/llvm/build_list.rs b/compiler/gen_llvm/src/llvm/build_list.rs
index 5c42d24c52..d46d454458 100644
--- a/compiler/gen_llvm/src/llvm/build_list.rs
+++ b/compiler/gen_llvm/src/llvm/build_list.rs
@@ -172,6 +172,7 @@ pub fn list_reverse<'a, 'ctx, 'env>(
     env: &Env<'a, 'ctx, 'env>,
     list: BasicValueEnum<'ctx>,
     list_layout: &Layout<'a>,
+    update_mode: UpdateMode,
 ) -> BasicValueEnum<'ctx> {
     let element_layout = match *list_layout {
         Layout::Builtin(Builtin::EmptyList) => {
@@ -190,6 +191,7 @@ pub fn list_reverse<'a, 'ctx, 'env>(
             pass_list_cc(env, list),
             env.alignment_intvalue(&element_layout),
             layout_width(env, &element_layout),
+            pass_update_mode(env, update_mode),
         ],
         bitcode::LIST_REVERSE,
     )
diff --git a/compiler/mono/src/alias_analysis.rs b/compiler/mono/src/alias_analysis.rs
index f0dc294a95..b218875425 100644
--- a/compiler/mono/src/alias_analysis.rs
+++ b/compiler/mono/src/alias_analysis.rs
@@ -918,6 +918,17 @@ fn lowlevel_spec(
             let new_cell = builder.add_new_heap_cell(block)?;
             builder.add_make_tuple(block, &[new_cell, bag])
         }
+        ListReverse => {
+            let list = env.symbols[&arguments[0]];
+
+            let bag = builder.add_get_tuple_field(block, list, LIST_BAG_INDEX)?;
+            let cell = builder.add_get_tuple_field(block, list, LIST_CELL_INDEX)?;
+
+            let _unit = builder.add_update(block, update_mode_var, cell)?;
+
+            let new_cell = builder.add_new_heap_cell(block)?;
+            builder.add_make_tuple(block, &[new_cell, bag])
+        }
         ListAppend => {
             let list = env.symbols[&arguments[0]];
             let to_insert = env.symbols[&arguments[1]];