diff --git a/KLR/Trace/Term.lean b/KLR/Trace/Term.lean
index a11cfdaa..4b5a6b9d 100644
--- a/KLR/Trace/Term.lean
+++ b/KLR/Trace/Term.lean
@@ -279,10 +279,16 @@ def toIndex (shape : List Nat) (ts : List Term) : Err (List Index) := do
     | _ => ts
   toIndex' shape ts
 
+-- Container type information for preserving original types during access
+inductive ContainerType where
+  | tuple : ContainerType
+  | list : ContainerType
+  deriving Repr, BEq
+
 -- Note, a list index can be negative, which means index from end of list.
 -- Python also allows l[True] and l[False]
 -- TODO: add case for slice
-def listAccess (l : List Term) : List Term -> Err Term
+def listAccess (l : List Term) (containerType : Option ContainerType := none) : List Term -> Err Term
   | [.bool false] => do
       if h:l.length > 0 then return l.get (Fin.mk 0 h)
       else throw "index out of bounds"
@@ -306,7 +312,9 @@ def listAccess (l : List Term) : List Term -> Err Term
         throw "slice index out of bounds"
       let sliced := List.range ((e - start + step - 1) / step).toNat |>.map fun i =>
         l[start.toNat + i * step.toNat]!
-      return .list sliced.toArray
+      match containerType with
+      | some .tuple => return .tuple sliced
+      | some .list | none => return .list sliced.toArray
   | e => throw s!"index must be an integer or slice, got {repr e}"
 
 def dictAccess (arr : AA) : List Term -> Err Term
@@ -408,8 +416,8 @@ partial def access (e : Term) (indexes : List Term) : Trace Term := do
   match e with
   | .ref name _ => access (<- lookup name) indexes
   | .string _ => throw "string subscript not implemented"
-  | .tuple l => listAccess l indexes
-  | .list l => listAccess l.toList indexes
+  | .tuple l => listAccess l (some .tuple) indexes
+  | .list l => listAccess l.toList (some .list) indexes
   | .dict arr => dictAccess arr indexes
   | .pointer addr => pointerAccess addr indexes
   | .access (.simple tensor) => do