diff --git a/lib/eval.ml b/lib/eval.ml
index 63f0c46..a4dd1f3 100644
--- a/lib/eval.ml
+++ b/lib/eval.ml
@@ -16,7 +16,7 @@ and function_type = {
 let rec eval_expr (scope: scope) (expr: Parser.expr_tree): value_type = 
   match expr with
   | Parser.LetExpr (l) -> 
-    eval_let_expr scope l.name l.value_expr l.in_expr
+    eval_let_expr scope l
   | Parser.FunExpr (ftree) -> 
     eval_fun_expr scope ftree
   | Parser.IfExpr (Parser.If (cond_expr, then_expr, else_expr)) -> 
@@ -50,7 +50,12 @@ and eval_if_expr scope cond_expr then_expr else_expr =
   (match cond with
   | Int 0 -> eval_expr scope else_expr
   | _ -> eval_expr scope then_expr)
-and eval_let_expr scope name value_expr in_expr =
+and eval_let_expr scope ({
+  name = name;
+  value_expr = value_expr;
+  in_expr = in_expr;
+  type_declare = _;
+}: Parser.let_expr_tree) =
   let value = eval_expr scope value_expr in
   let new_scope = { scope with bindings = VariableBindingMap.add name value scope.bindings } in
   eval_expr new_scope in_expr