diff --git a/nac3artiq/src/lib.rs b/nac3artiq/src/lib.rs
index a180a28..1d7c476 100644
--- a/nac3artiq/src/lib.rs
+++ b/nac3artiq/src/lib.rs
@@ -78,9 +78,7 @@ struct Nac3 {
     builtins_ty: HashMap<StrRef, Type>,
     builtins_def: HashMap<StrRef, DefinitionId>,
     pyid_to_def: Arc<RwLock<HashMap<u64, DefinitionId>>>,
-    pyid_to_type: Arc<RwLock<HashMap<u64, Type>>>,
     primitive_ids: PrimitivePythonId,
-    global_value_ids: Arc<RwLock<HashSet<u64>>>,
     working_directory: TempDir,
     top_levels: Vec<TopLevelComponent>,
 }
@@ -406,8 +404,6 @@ impl Nac3 {
             primitive_ids,
             top_levels: Default::default(),
             pyid_to_def: Default::default(),
-            pyid_to_type: Default::default(),
-            global_value_ids: Default::default(),
             working_directory,
         })
     }
@@ -451,8 +447,6 @@ impl Nac3 {
             kernel_ann: Some("Kernel"),
             kernel_invariant_ann: "KernelInvariant"
         });
-        let mut id_to_def = HashMap::new();
-        let mut id_to_type = HashMap::new();
 
         let builtins = PyModule::import(py, "builtins")?;
         let typings = PyModule::import(py, "typing")?;
@@ -466,6 +460,8 @@ impl Nac3 {
         };
         let mut module_to_resolver_cache: HashMap<u64, _> = HashMap::new();
 
+        let pyid_to_type = Arc::new(RwLock::new(HashMap::<u64, Type>::new()));
+        let global_value_ids = Arc::new(RwLock::new(HashSet::<u64>::new()));
         for (stmt, path, module) in self.top_levels.iter() {
             let py_module: &PyAny = module.extract(py)?;
             let module_id: u64 = id_fn.call1((py_module,))?.extract()?;
@@ -486,9 +482,9 @@ impl Nac3 {
                         id_to_type: self.builtins_ty.clone().into(),
                         id_to_def: self.builtins_def.clone().into(),
                         pyid_to_def: self.pyid_to_def.clone(),
-                        pyid_to_type: self.pyid_to_type.clone(),
+                        pyid_to_type: pyid_to_type.clone(),
                         primitive_ids: self.primitive_ids.clone(),
-                        global_value_ids: self.global_value_ids.clone(),
+                        global_value_ids: global_value_ids.clone(),
                         class_names: Default::default(),
                         name_to_pyid: name_to_pyid.clone(),
                         module: module.clone(),
@@ -508,19 +504,12 @@ impl Nac3 {
                 .register_top_level(stmt.clone(), Some(resolver.clone()), path.clone())
                 .map_err(|e| exceptions::PyRuntimeError::new_err(format!("nac3 compilation failure: {}", e)))?;
             let id = *name_to_pyid.get(&name).unwrap();
-            id_to_def.insert(id, def_id);
-            if let Some(ty) = ty {
-                id_to_type.insert(id, ty);
-            }
-        }
-        {
-            let mut map = self.pyid_to_def.write();
-            for (id, def) in id_to_def.into_iter() {
-                map.insert(id, def);
-            }
-            let mut map = self.pyid_to_type.write();
-            for (id, ty) in id_to_type.into_iter() {
-                map.insert(id, ty);
+            self.pyid_to_def.write().insert(id, def_id);
+            {
+                let mut pyid_to_ty = pyid_to_type.write();
+                if let Some(ty) = ty {
+                    pyid_to_ty.insert(id, ty);
+                }
             }
         }
 
@@ -553,9 +542,9 @@ impl Nac3 {
             id_to_type: self.builtins_ty.clone().into(),
             id_to_def: self.builtins_def.clone().into(),
             pyid_to_def: self.pyid_to_def.clone(),
-            pyid_to_type: self.pyid_to_type.clone(),
+            pyid_to_type: pyid_to_type.clone(),
             primitive_ids: self.primitive_ids.clone(),
-            global_value_ids: self.global_value_ids.clone(),
+            global_value_ids: global_value_ids.clone(),
             class_names: Default::default(),
             id_to_pyval: Default::default(),
             id_to_primitive: Default::default(),