diff --git a/Cargo.lock b/Cargo.lock
index c85aee3..652763d 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -252,8 +252,9 @@ checksum = "7fcaabb2fef8c910e7f4c7ce9f67a1283a1715879a7c230ca9d6d1ae31f16d91"
 
 [[package]]
 name = "els"
-version = "0.1.19-nightly.2"
-source = "git+https://github.com/erg-lang/erg?branch=main#228a74d29d83907ffcb62dd849036200bd167c06"
+version = "0.1.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "94694dcfb56e12207fb27ff73158b9fb759497485790c71de98aa4b0136c72f6"
 dependencies = [
  "erg_common",
  "erg_compiler",
@@ -273,8 +274,9 @@ dependencies = [
 
 [[package]]
 name = "erg_common"
-version = "0.6.7-nightly.2"
-source = "git+https://github.com/erg-lang/erg?branch=main#228a74d29d83907ffcb62dd849036200bd167c06"
+version = "0.6.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "88c9d058b405901b41dbc282f9927fd5295dc46c50fa2f8fc75f2c3d7783ac77"
 dependencies = [
  "backtrace-on-stack-overflow",
  "hermit-abi",
@@ -284,8 +286,9 @@ dependencies = [
 
 [[package]]
 name = "erg_compiler"
-version = "0.6.7-nightly.2"
-source = "git+https://github.com/erg-lang/erg?branch=main#228a74d29d83907ffcb62dd849036200bd167c06"
+version = "0.6.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ffb25a8403805eb864bb3f56c920dfafadca30bf2ff8be5c733d3449e16ae224"
 dependencies = [
  "erg_common",
  "erg_parser",
@@ -293,8 +296,9 @@ dependencies = [
 
 [[package]]
 name = "erg_parser"
-version = "0.6.7-nightly.2"
-source = "git+https://github.com/erg-lang/erg?branch=main#228a74d29d83907ffcb62dd849036200bd167c06"
+version = "0.6.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ea28285bc487cc9807beafd63664c0903bf8bca86c5ac692dd8a3b783c03bdb7"
 dependencies = [
  "erg_common",
  "unicode-xid 0.2.4",
diff --git a/Cargo.toml b/Cargo.toml
index 6474449..f14d6a3 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -22,13 +22,13 @@ edition = "2021"
 repository = "https://github.com/mtshiba/pylyzer"
 
 [workspace.dependencies]
-# erg_common = { version = "0.6.7-nightly.2", features = ["py_compatible", "els"] }
-# erg_compiler = { version = "0.6.7-nightly.2", features = ["py_compatible", "els"] }
-# els = { version = "0.1.19-nightly.2", features = ["py_compatible"] }
+erg_common = { version = "0.6.7", features = ["py_compatible", "els"] }
+erg_compiler = { version = "0.6.7", features = ["py_compatible", "els"] }
+els = { version = "0.1.19", features = ["py_compatible"] }
 rustpython-parser = "0.1.2"
-erg_compiler = { git = "https://github.com/erg-lang/erg", branch = "main", features = ["py_compatible", "els"] }
-erg_common = { git = "https://github.com/erg-lang/erg", branch = "main", features = ["py_compatible", "els"] }
-els = { git = "https://github.com/erg-lang/erg", branch = "main", features = ["py_compatible"] }
+# erg_compiler = { git = "https://github.com/erg-lang/erg", branch = "main", features = ["py_compatible", "els"] }
+# erg_common = { git = "https://github.com/erg-lang/erg", branch = "main", features = ["py_compatible", "els"] }
+# els = { git = "https://github.com/erg-lang/erg", branch = "main", features = ["py_compatible"] }
 
 [features]
 debug = ["erg_compiler/debug", "erg_common/debug", "py2erg/debug"]
diff --git a/README.md b/README.md
index d679d01..d012ab7 100644
--- a/README.md
+++ b/README.md
@@ -4,7 +4,7 @@
 <a href="https://github.com/mtshiba/pylyzer/releases"><img alt="Build status" src="https://img.shields.io/github/v/release/mtshiba/pylyzer.svg"></a>
 <a href="https://github.com/mtshiba/pylyzer/actions/workflows/rust.yml"><img alt="Build status" src="https://github.com/mtshiba/pylyzer/actions/workflows/rust.yml/badge.svg"></a>
 
-`pylyzer` is a static code analyzer / language server for Python written in Rust.
+`pylyzer` is a static code analyzer / language server for Python, written in Rust.
 
 ## Installation
 
@@ -20,8 +20,7 @@ cargo install pylyzer
 pip install pylyzer
 ```
 
-If installed this way, type resolution for the standard libraries is not available.
-If you want to use it, you need to [install Erg](https://github.com/mtshiba/ergup).
+If installed this way, you also need to [install Erg](https://github.com/mtshiba/ergup).
 
 ```bash
 curl -L https://github.com/mtshiba/ergup/raw/main/ergup.py | python3
diff --git a/crates/py2erg/convert.rs b/crates/py2erg/convert.rs
index 7e4cd63..78bf1ce 100644
--- a/crates/py2erg/convert.rs
+++ b/crates/py2erg/convert.rs
@@ -1019,7 +1019,7 @@ impl ASTConverter {
             ConstArgs::empty(),
         )));
         let sig = Signature::Subr(SubrSignature::new(
-            HashSet::new(),
+            set! { Decorator(Expr::static_local("Override")) },
             call_ident,
             TypeBoundSpecs::empty(),
             params,
@@ -1046,7 +1046,7 @@ impl ASTConverter {
             ConstArgs::empty(),
         )));
         let sig = Signature::Subr(SubrSignature::new(
-            HashSet::new(),
+            set! { Decorator(Expr::static_local("Override")) },
             call_ident,
             TypeBoundSpecs::empty(),
             params,
@@ -1059,13 +1059,23 @@ impl ASTConverter {
         Def::new(sig, body)
     }
 
-    fn extract_method(&mut self, body: Vec<Located<StatementType>>) -> (Option<Expr>, ClassAttrs) {
+    fn extract_method(
+        &mut self,
+        body: Vec<Located<StatementType>>,
+        inherit: bool,
+    ) -> (Option<Expr>, ClassAttrs) {
         let mut base_type = None;
         let mut attrs = vec![];
         let mut init_is_defined = false;
         for stmt in body {
             match self.convert_statement(stmt, true) {
-                Expr::Def(def) => {
+                Expr::Def(mut def) => {
+                    if inherit {
+                        if let Signature::Subr(subr) = &mut def.sig {
+                            subr.decorators
+                                .insert(Decorator(Expr::static_local("Override")));
+                        }
+                    }
                     if def
                         .sig
                         .ident()
@@ -1124,7 +1134,7 @@ impl ASTConverter {
                 _other => {} // TODO:
             }
         }
-        if !init_is_defined {
+        if !init_is_defined && !inherit {
             attrs.insert(0, ClassAttr::Def(self.gen_default_init(0)));
         }
         (base_type, ClassAttrs::new(attrs))
@@ -1134,13 +1144,14 @@ impl ASTConverter {
         &mut self,
         ident: Identifier,
         body: Vec<Located<StatementType>>,
+        inherit: bool,
     ) -> (Option<Expr>, Vec<Methods>) {
         let class = TypeSpec::PreDeclTy(PreDeclTypeSpec::Simple(SimpleTypeSpec::new(
             ident.clone(),
             ConstArgs::empty(),
         )));
         let class_as_expr = Expr::Accessor(Accessor::Ident(ident));
-        let (base_type, attrs) = self.extract_method(body);
+        let (base_type, attrs) = self.extract_method(body, inherit);
         let methods = Methods::new(class, class_as_expr, VisModifierSpec::Public(DOT), attrs);
         (base_type, vec![methods])
     }
@@ -1205,6 +1216,13 @@ impl ASTConverter {
     /// ```erg
     /// Foo = Inheritable Class()
     /// ```
+    /// ```python
+    /// class Foo(Bar): pass
+    /// ```
+    /// ↓
+    /// ```erg
+    /// Foo = Inherit Bar
+    /// ```
     fn convert_classdef(
         &mut self,
         name: String,
@@ -1217,34 +1235,48 @@ impl ASTConverter {
             .into_iter()
             .map(|deco| self.convert_expr(deco))
             .collect::<Vec<_>>();
-        let _bases = bases
+        let mut bases = bases
             .into_iter()
             .map(|base| self.convert_expr(base))
             .collect::<Vec<_>>();
+        let inherit = !bases.is_empty();
         self.register_name_info(&name, NameKind::Class);
         let class_name_loc = PyLocation::new(loc.row(), loc.column() + 6);
         let ident = self.convert_ident(name, class_name_loc);
         let sig = Signature::Var(VarSignature::new(VarPattern::Ident(ident.clone()), None));
         self.namespace.push(ident.inspect().to_string());
-        let (base_type, methods) = self.extract_method_list(ident, body);
-        let pos_args = if let Some(base) = base_type {
-            vec![PosArg::new(base)]
+        let (base_type, methods) = self.extract_method_list(ident, body, inherit);
+        let classdef = if inherit {
+            // TODO: multiple inheritance
+            let pos_args = vec![PosArg::new(bases.remove(0))];
+            let args = Args::pos_only(pos_args, None);
+            let inherit_acc = Expr::Accessor(Accessor::Ident(
+                self.convert_ident("Inherit".to_string(), loc),
+            ));
+            let inherit_call = inherit_acc.call_expr(args);
+            let body = DefBody::new(EQUAL, Block::new(vec![inherit_call]), DefId(0));
+            let def = Def::new(sig, body);
+            ClassDef::new(def, methods)
         } else {
-            vec![]
+            let pos_args = if let Some(base) = base_type {
+                vec![PosArg::new(base)]
+            } else {
+                vec![]
+            };
+            let args = Args::pos_only(pos_args, None);
+            let class_acc = Expr::Accessor(Accessor::Ident(
+                self.convert_ident("Class".to_string(), loc),
+            ));
+            let class_call = class_acc.call_expr(args);
+            let inheritable_acc = Expr::Accessor(Accessor::Ident(
+                self.convert_ident("Inheritable".to_string(), loc),
+            ));
+            let inheritable_call =
+                inheritable_acc.call_expr(Args::pos_only(vec![PosArg::new(class_call)], None));
+            let body = DefBody::new(EQUAL, Block::new(vec![inheritable_call]), DefId(0));
+            let def = Def::new(sig, body);
+            ClassDef::new(def, methods)
         };
-        let args = Args::pos_only(pos_args, None);
-        let class_acc = Expr::Accessor(Accessor::Ident(
-            self.convert_ident("Class".to_string(), loc),
-        ));
-        let class_call = class_acc.call_expr(args);
-        let inheritable_acc = Expr::Accessor(Accessor::Ident(
-            self.convert_ident("Inheritable".to_string(), loc),
-        ));
-        let inheritable_call =
-            inheritable_acc.call_expr(Args::pos_only(vec![PosArg::new(class_call)], None));
-        let body = DefBody::new(EQUAL, Block::new(vec![inheritable_call]), DefId(0));
-        let def = Def::new(sig, body);
-        let classdef = ClassDef::new(def, methods);
         self.namespace.pop();
         Expr::ClassDef(classdef)
     }
diff --git a/tests/class.py b/tests/class.py
index c73515a..0ec9174 100644
--- a/tests/class.py
+++ b/tests/class.py
@@ -36,11 +36,19 @@ class D:
         return D(self.c - other.x)
     def __neg__(self):
         return D(-self.c)
+    def __gt__(self, other: D):
+        return self.c > other.c
     def __init__(self, c):
         self.c = c
 
+class E(D):
+    def __add__(self, other: E):
+        return E(self.c + other.c)
+
 c1 = D(1).c + 1
 d = D(1) + D(2)
 err = C(1, 2) + D(1) # ERR
 ok = D(1) - C(1, 2) # OK
+assert D(1) > D(0)
 c = -d # OK
+e = E(1)