diff --git a/src/protocol/parser/mod.rs b/src/protocol/parser/mod.rs
index 4688c9fe5e963e7877606b9384ae685762c2521c..3dca61f0109c63bbe526e10dfd69e8e9cbf6feeb 100644
--- a/src/protocol/parser/mod.rs
+++ b/src/protocol/parser/mod.rs
@@ -282,23 +282,24 @@ fn insert_builtin_function<T: Fn(FunctionDefinitionId) -> (Vec<(&'static str, Pa
         span: InputSpan::new(),
         identifier: Identifier{ span: InputSpan::new(), value: func_ident_ref.clone() },
         poly_vars,
-        return_types: Vec::new(),
+        return_type: ParserType{ elements: Vec::new(), full_span: InputSpan::new() },
         parameters: Vec::new(),
+        scope: ScopeId::new_invalid(),
         body: BlockStatementId::new_invalid(),
         num_expressions_in_body: -1,
     });
 
-    let (args, ret) = arg_and_return_fn(func_id);
+    let (arguments, return_type) = arg_and_return_fn(func_id);
 
-    let mut parameters = Vec::with_capacity(args.len());
-    for (arg_name, arg_type) in args {
+    let mut parameters = Vec::with_capacity(arguments.len());
+    for (arg_name, arg_type) in arguments {
         let identifier = Identifier{ span: InputSpan::new(), value: p.string_pool.intern(arg_name.as_bytes()) };
         let param_id = p.heap.alloc_variable(|this| Variable{
             this,
             kind: VariableKind::Parameter,
             parser_type: arg_type.clone(),
             identifier,
-            relative_pos_in_block: 0,
+            relative_pos_in_parent: 0,
             unique_id_in_scope: 0
         });
         parameters.push(param_id);
@@ -306,7 +307,7 @@ fn insert_builtin_function<T: Fn(FunctionDefinitionId) -> (Vec<(&'static str, Pa
 
     let func = &mut p.heap[func_id];
     func.parameters = parameters;
-    func.return_types.push(ret);
+    func.return_type = return_type;
 
     p.symbol_table.insert_symbol(SymbolScope::Global, Symbol{
         name: func_ident_ref,