diff --git a/nac3artiq/src/symbol_resolver.rs b/nac3artiq/src/symbol_resolver.rs
index eb123d753..e177b1ff6 100644
--- a/nac3artiq/src/symbol_resolver.rs
+++ b/nac3artiq/src/symbol_resolver.rs
@@ -512,8 +512,8 @@ impl InnerResolver {
         primitives: &PrimitiveStore,
     ) -> PyResult<Result<Type, String>> {
         let ty = self.helper.type_fn.call1(py, (obj,)).unwrap();
-        let ty_id: u64 = self.helper.id_fn.call1(py, (ty.clone(),))?.extract(py)?;
-        if let Some(ty) = self.pyid_to_type.read().get(&ty_id) {
+        let py_obj_id: u64 = self.helper.id_fn.call1(py, (obj,))?.extract(py)?;
+        if let Some(ty) = self.pyid_to_type.read().get(&py_obj_id) {
             return Ok(Ok(*ty))
         }
         let (extracted_ty, inst_check) = match self.get_pyty_obj_type(
@@ -620,6 +620,7 @@ impl InnerResolver {
                 Ok(Ok(res))
             }
             (TypeEnum::TObj { params, fields, .. }, false) => {
+                self.pyid_to_type.write().insert(py_obj_id, extracted_ty);
                 let var_map = params
                     .iter()
                     .map(|(id_var, ty)| {
@@ -673,7 +674,13 @@ impl InnerResolver {
                     let extracted_ty = unifier.subst(extracted_ty, &var_map).unwrap_or(extracted_ty);
                     Ok(Ok(extracted_ty))
                 };
-                instantiate_obj()
+                let result = instantiate_obj();
+                // update/remove the cache according to the result
+                match result {
+                    Ok(Ok(ty)) => self.pyid_to_type.write().insert(py_obj_id, ty),
+                    _ => self.pyid_to_type.write().remove(&py_obj_id)
+                };
+                result
             }
             _ => Ok(Ok(extracted_ty)),
         }
@@ -918,7 +925,9 @@ impl InnerResolver {
                 let values = values?;
                 if let Some(values) = values {
                     let val = ty.const_named_struct(&values);
-                    let global = ctx.module.add_global(ty, Some(AddressSpace::Generic), &id_str);
+                    let global = ctx.module.get_global(&id_str).unwrap_or_else(|| {
+                        ctx.module.add_global(ty, Some(AddressSpace::Generic), &id_str)
+                    });
                     global.set_initializer(&val);
                     Ok(Some(global.as_pointer_value().into()))
                 } else {