diff --git a/schala-lang/language/src/ast/mod.rs b/schala-lang/language/src/ast/mod.rs
index f0883d5..0c4a5cd 100644
--- a/schala-lang/language/src/ast/mod.rs
+++ b/schala-lang/language/src/ast/mod.rs
@@ -11,7 +11,8 @@ pub use visitor::ASTVisitor;
 pub use walker::walk_ast;
 use crate::tokenizing::Location;
 
-/// An abstract identifier for an AST node
+/// An abstract identifier for an AST node. Note that
+/// the u32 index limits the size of an AST to 2^32 nodes.
 #[derive(Debug, PartialEq, Eq, Hash, Clone, Default)]
 pub struct ItemId {
   idx: u32,
@@ -31,13 +32,7 @@ impl ItemIdStore {
   pub fn new() -> ItemIdStore {
     ItemIdStore { last_idx: 0 }
   }
-  /// Always returns an ItemId with internal value zero
-  #[cfg(test)]
-  pub fn new_id() -> ItemId {
-    ItemId { idx: 0 }
-  }
 
-  /// This limits the size of the AST to 2^32 tree elements
   pub fn fresh(&mut self) -> ItemId {
     let idx = self.last_idx;
     self.last_idx += 1;
diff --git a/schala-lang/language/src/parsing/test.rs b/schala-lang/language/src/parsing/test.rs
index 9bfdfe4..576ef63 100644
--- a/schala-lang/language/src/parsing/test.rs
+++ b/schala-lang/language/src/parsing/test.rs
@@ -45,7 +45,7 @@ macro_rules! parse_test {
   };
 }
 macro_rules! parse_test_wrap_ast {
-  ($string:expr, $correct:expr) => { parse_test!($string, AST { id: ItemIdStore::new_id(), statements: vec![$correct] }) }
+  ($string:expr, $correct:expr) => { parse_test!($string, AST { id: Default::default(), statements: vec![$correct] }) }
 }
 macro_rules! parse_error {
   ($string:expr) => { assert!(parse($string).is_err()) }
@@ -57,12 +57,12 @@ macro_rules! qname {
     $(
       components.push(rc!($component));
     )*
-    QualifiedName { components, id: ItemIdStore::new_id() }
+    QualifiedName { components, id: Default::default() }
     }
   };
 }
 macro_rules! val {
-  ($var:expr) => { Value(QualifiedName { components: vec![Rc::new($var.to_string())], id: ItemIdStore::new_id() }) };
+  ($var:expr) => { Value(QualifiedName { components: vec![Rc::new($var.to_string())], id: Default::default() }) };
 }
 macro_rules! ty {
   ($name:expr) => { Singleton(tys!($name)) }
@@ -90,8 +90,8 @@ macro_rules! module {
 }
 
 macro_rules! ex {
-  ($expr_type:expr) => { Expression::new(ItemIdStore::new_id(), $expr_type) };
-  ($expr_type:expr, $type_anno:expr) => { Expression::with_anno(ItemIdStore::new_id(), $expr_type, $type_anno) };
+  ($expr_type:expr) => { Expression::new(Default::default(), $expr_type) };
+  ($expr_type:expr, $type_anno:expr) => { Expression::with_anno(Default::default(), $expr_type, $type_anno) };
   (s $expr_text:expr) => {
     {
       let mut parser = make_parser($expr_text);
@@ -105,14 +105,14 @@ macro_rules! inv {
 }
 
 macro_rules! binexp {
-  ($op:expr, $lhs:expr, $rhs:expr) => { BinExp(BinOp::from_sigil($op), bx!(Expression::new(ItemIdStore::new_id(), $lhs).into()), bx!(Expression::new(ItemIdStore::new_id(), $rhs).into())) }
+  ($op:expr, $lhs:expr, $rhs:expr) => { BinExp(BinOp::from_sigil($op), bx!(Expression::new(Default::default(), $lhs).into()), bx!(Expression::new(Default::default(), $rhs).into())) }
 }
 macro_rules! prefexp {
-  ($op:expr, $lhs:expr) => { PrefixExp(PrefixOp::from_sigil($op), bx!(Expression::new(ItemIdStore::new_id(), $lhs).into())) }
+  ($op:expr, $lhs:expr) => { PrefixExp(PrefixOp::from_sigil($op), bx!(Expression::new(Default::default(), $lhs).into())) }
 }
 macro_rules! exst {
-  ($expr_type:expr) => { make_statement(StatementKind::Expression(Expression::new(ItemIdStore::new_id(), $expr_type).into())) };
-  ($expr_type:expr, $type_anno:expr) => { make_statement(StatementKind::Expression(Expression::with_anno(ItemIdStore::new_id(), $expr_type, $type_anno).into())) };
+  ($expr_type:expr) => { make_statement(StatementKind::Expression(Expression::new(Default::default(), $expr_type).into())) };
+  ($expr_type:expr, $type_anno:expr) => { make_statement(StatementKind::Expression(Expression::with_anno(Default::default(), $expr_type, $type_anno).into())) };
   ($op:expr, $lhs:expr, $rhs:expr) => { make_statement(StatementKind::Expression(ex!(binexp!($op, $lhs, $rhs)))) };
   (s $statement_text:expr) => {
     {
@@ -137,7 +137,7 @@ fn parsing_number_literals_and_binexps() {
 
   parse_test! {"3; 4; 4.3",
     AST {
-      id: ItemIdStore::new_id(),
+      id: Default::default(),
       statements: vec![exst!(NatLiteral(3)), exst!(NatLiteral(4)),
       exst!(FloatLiteral(4.3))]
     }
@@ -217,7 +217,7 @@ fn qualified_identifiers() {
   parse_test_wrap_ast! {
     "let q_q = Yolo::Swaggins",
     decl!(Binding { name: rc!(q_q), constant: true, type_anno: None,
-    expr: Expression::new(ItemIdStore::new_id(), Value(qname!(Yolo, Swaggins))),
+    expr: Expression::new(Default::default(), Value(qname!(Yolo, Swaggins))),
     })
   }
 
@@ -583,7 +583,7 @@ fn more_advanced_lambdas() {
     r#"fn wahoo() { let a = 10; \(x) { x + a } };
     wahoo()(3) "#,
     AST {
-      id: ItemIdStore::new_id(),
+      id: Default::default(),
       statements: vec![
         exst!(s r"fn wahoo() { let a = 10; \(x) { x + a } }"),
         exst! {
@@ -746,7 +746,7 @@ fn imports() {
   parse_test_wrap_ast! {
     "import harbinger::draughts::Norgleheim",
     import!(ImportSpecifier { 
-      id: ItemIdStore::new_id(),
+      id: Default::default(),
       path_components: vec![rc!(harbinger), rc!(draughts), rc!(Norgleheim)],
       imported_names: ImportedNames::LastOfPath
     })
@@ -758,7 +758,7 @@ fn imports_2() {
   parse_test_wrap_ast! {
     "import harbinger::draughts::{Norgleheim, Xraksenlaigar}",
     import!(ImportSpecifier { 
-      id: ItemIdStore::new_id(),
+      id: Default::default(),
       path_components: vec![rc!(harbinger), rc!(draughts)],
       imported_names: ImportedNames::List(vec![
         rc!(Norgleheim),
@@ -773,7 +773,7 @@ fn imports_3() {
   parse_test_wrap_ast! {
     "import bespouri::{}",
     import!(ImportSpecifier { 
-      id: ItemIdStore::new_id(),
+      id: Default::default(),
       path_components: vec![rc!(bespouri)],
       imported_names: ImportedNames::List(vec![])
     })
@@ -786,7 +786,7 @@ fn imports_4() {
   parse_test_wrap_ast! {
     "import bespouri::*",
     import!(ImportSpecifier {
-      id: ItemIdStore::new_id(),
+      id: Default::default(),
       path_components: vec![rc!(bespouri)],
       imported_names: ImportedNames::All
     })