diff --git a/nac3artiq/src/symbol_resolver.rs b/nac3artiq/src/symbol_resolver.rs
index 152b5975..4c2dd5cd 100644
--- a/nac3artiq/src/symbol_resolver.rs
+++ b/nac3artiq/src/symbol_resolver.rs
@@ -503,7 +503,7 @@ impl InnerResolver {
             Ok(s) => s,
             Err(e) => return Ok(Err(e)),
         };
-        return match (&*unifier.get_ty(extracted_ty), inst_check) {
+        match (&*unifier.get_ty(extracted_ty), inst_check) {
             // do the instantiation for these three types
             (TypeEnum::TList { ty }, false) => {
                 let len: usize = self.helper.len_fn.call1(py, (obj,))?.extract(py)?;
@@ -538,22 +538,9 @@ impl InnerResolver {
                 let types = types?;
                 Ok(types.map(|types| unifier.add_ty(TypeEnum::TTuple { ty: types })))
             }
-            (TypeEnum::TObj { params, fields, .. }, false) => {
+            (TypeEnum::TObj { params: var_map, fields, .. }, false) => {
                 self.pyid_to_type.write().insert(ty_id, extracted_ty);
                 let mut instantiate_obj = || {
-                    let var_map = params
-                        .iter()
-                        .map(|(id_var, ty)| {
-                            if let TypeEnum::TVar { id, range, name, loc, .. } =
-                                &*unifier.get_ty(*ty)
-                            {
-                                assert_eq!(*id, *id_var);
-                                (*id, unifier.get_fresh_var_with_range(range, *name, *loc).0)
-                            } else {
-                                unreachable!()
-                            }
-                        })
-                        .collect::<HashMap<_, _>>();
                     // loop through non-function fields of the class to get the instantiated value
                     for field in fields.iter() {
                         let name: String = (*field.0).into();
@@ -590,7 +577,7 @@ impl InnerResolver {
                             return Ok(Err("object is not of concrete type".into()));
                         }
                     }
-                    Ok(Ok(unifier.subst(extracted_ty, &var_map).unwrap_or(extracted_ty)))
+                    Ok(Ok(extracted_ty))
                 };
                 let result = instantiate_obj();
                 // do not cache the type if there are errors
@@ -600,7 +587,7 @@ impl InnerResolver {
                 result
             }
             _ => Ok(Ok(extracted_ty)),
-        };
+        }
     }
 
     fn get_obj_value<'ctx, 'a>(
@@ -919,6 +906,7 @@ impl SymbolResolver for Resolver {
                     })
                     .unwrap(),
                 };
+                println!("{:?}", result);
                 if let Ok(t) = &result {
                     self.0.id_to_type.write().insert(str, *t);
                 }
diff --git a/nac3core/src/symbol_resolver.rs b/nac3core/src/symbol_resolver.rs
index 186453f2..d5df9f2a 100644
--- a/nac3core/src/symbol_resolver.rs
+++ b/nac3core/src/symbol_resolver.rs
@@ -229,10 +229,10 @@ pub fn parse_type_annotation<T>(
                         Err(format!("Cannot use function name as type at {}", loc))
                     }
                 }
-                Err(e) => {
+                Err(_) => {
                     let ty = resolver
                         .get_symbol_type(unifier, top_level_defs, primitives, *id)
-                        .map_err(|_| format!("Unknown type annotation at {}: {}", loc, e))?;
+                        .map_err(|e| format!("Unknown type annotation at {}: {}", loc, e))?;
                     if let TypeEnum::TVar { .. } = &*unifier.get_ty(ty) {
                         Ok(ty)
                     } else {
diff --git a/nac3core/src/toplevel/composer.rs b/nac3core/src/toplevel/composer.rs
index 83cd9cee..5d660533 100644
--- a/nac3core/src/toplevel/composer.rs
+++ b/nac3core/src/toplevel/composer.rs
@@ -1,4 +1,5 @@
 use nac3parser::ast::fold::Fold;
+use std::rc::Rc;
 
 use crate::{
     codegen::{expr::get_subst_key, stmt::exn_constructor},
@@ -1192,18 +1193,9 @@ impl TopLevelComposer {
                                     unreachable!("must be type var annotation");
                                 }
                             }
-                            let dummy_return_type = unifier.get_dummy_var().0;
-                            type_var_to_concrete_def.insert(dummy_return_type, annotation.clone());
-                            dummy_return_type
+                            get_type_from_type_annotation_kinds(temp_def_list, unifier, primitives, &annotation)?
                         } else {
-                            // if do not have return annotation, return none
-                            // for uniform handling, still use type annoatation
-                            let dummy_return_type = unifier.get_dummy_var().0;
-                            type_var_to_concrete_def.insert(
-                                dummy_return_type,
-                                TypeAnnotation::Primitive(primitives.none),
-                            );
-                            dummy_return_type
+                            primitives.none
                         }
                     };
 
@@ -1449,6 +1441,34 @@ impl TopLevelComposer {
         let primitives_ty = &self.primitives_ty;
         let definition_ast_list = &self.definition_ast_list;
         let unifier = &mut self.unifier;
+
+        // first, fix function typevar ids
+        // they may be changed with our use of placeholders
+        for (def, _) in definition_ast_list.iter().skip(self.builtin_num) {
+            if let TopLevelDef::Function {
+                signature,
+                var_id,
+                ..
+            } = &mut *def.write() {
+                if let TypeEnum::TFunc(FunSignature { args, ret, vars }) =
+                        unifier.get_ty(*signature).as_ref() {
+                    let new_var_ids = vars.values().map(|v| match &*unifier.get_ty(*v) {
+                        TypeEnum::TVar{id, ..} => *id,
+                        _ => unreachable!(),
+                    }).collect_vec();
+                    if new_var_ids != *var_id {
+                        let new_signature = FunSignature {
+                            args: args.clone(),
+                            ret: ret.clone(),
+                            vars: new_var_ids.iter().zip(vars.values()).map(|(id, v)| (*id, v.clone())).collect(),
+                        };
+                        unifier.unification_table.set_value(*signature, Rc::new(TypeEnum::TFunc(new_signature)));
+                        *var_id = new_var_ids;
+                    }
+                }
+            }
+        }
+
         let mut errors = HashSet::new();
         let mut analyze = |i, def: &Arc<RwLock<TopLevelDef>>, ast: &Option<Stmt>| {
             let class_def = def.read();
@@ -1650,7 +1670,6 @@ impl TopLevelComposer {
                     // if class methods, `vars` also contains all class typevars here
                     let (type_var_subst_comb, no_range_vars) = {
                         let mut no_ranges: Vec<Type> = Vec::new();
-                        let var_ids = vars.keys().copied().collect_vec();
                         let var_combs = vars
                             .iter()
                             .map(|(_, ty)| {
@@ -1669,7 +1688,7 @@ impl TopLevelComposer {
                             .collect_vec();
                         let mut result: Vec<HashMap<u32, Type>> = Default::default();
                         for comb in var_combs {
-                            result.push(var_ids.clone().into_iter().zip(comb).collect());
+                            result.push(insted_vars.clone().into_iter().zip(comb).collect());
                         }
                         // NOTE: if is empty, means no type var, append a empty subst, ok to do this?
                         if result.is_empty() {
diff --git a/nac3core/src/toplevel/type_annotation.rs b/nac3core/src/toplevel/type_annotation.rs
index 9fc1f80c..3d15a760 100644
--- a/nac3core/src/toplevel/type_annotation.rs
+++ b/nac3core/src/toplevel/type_annotation.rs
@@ -105,8 +105,6 @@ pub fn parse_ast_to_type_annotation_kinds<T>(
             Ok(TypeAnnotation::CustomClass { id: obj_id, params: vec![] })
         } else if let Ok(ty) = resolver.get_symbol_type(unifier, top_level_defs, primitives, *id) {
             if let TypeEnum::TVar { .. } = unifier.get_ty(ty).as_ref() {
-                let var = unifier.get_fresh_var(Some(*id), Some(expr.location)).0;
-                unifier.unify(var, ty).unwrap();
                 Ok(TypeAnnotation::TypeVar(ty))
             } else {
                 Err(format!("`{}` is not a valid type annotation (at {})", id, expr.location))
diff --git a/nac3core/src/typecheck/typedef/mod.rs b/nac3core/src/typecheck/typedef/mod.rs
index b58c160b..b13628b8 100644
--- a/nac3core/src/typecheck/typedef/mod.rs
+++ b/nac3core/src/typecheck/typedef/mod.rs
@@ -156,9 +156,9 @@ pub type SharedUnifier = Arc<Mutex<(UnificationTable<TypeEnum>, u32, Vec<Call>)>
 
 #[derive(Clone)]
 pub struct Unifier {
-    pub top_level: Option<Arc<TopLevelContext>>,
-    unification_table: UnificationTable<Rc<TypeEnum>>,
-    pub(super) calls: Vec<Rc<Call>>,
+    pub(crate) top_level: Option<Arc<TopLevelContext>>,
+    pub(crate) unification_table: UnificationTable<Rc<TypeEnum>>,
+    pub(crate) calls: Vec<Rc<Call>>,
     var_id: u32,
     unify_cache: HashSet<(Type, Type)>,
     snapshot: Option<(usize, u32)>