diff --git a/Cargo.lock b/Cargo.lock
index 3a41beb..42c051a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -152,9 +152,9 @@ checksum = "7fcaabb2fef8c910e7f4c7ce9f67a1283a1715879a7c230ca9d6d1ae31f16d91"
 
 [[package]]
 name = "els"
-version = "0.1.27-nightly.0"
+version = "0.1.27-nightly.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "52d65a32e855c6093747f38e0c2d4049b0f38c4b74dea213bf5031b18ebca141"
+checksum = "27d9f6b1daecf4f75a6157caf93841f30bf28e194e8229ab69ff408fd9f836c1"
 dependencies = [
  "erg_common",
  "erg_compiler",
@@ -177,18 +177,18 @@ dependencies = [
 
 [[package]]
 name = "erg_common"
-version = "0.6.15-nightly.0"
+version = "0.6.15-nightly.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0fa2ce07958c54ec955967e0008f0aaa016122c1ec18b30ba2ddeffa9f61b3f2"
+checksum = "720647c8de2c9c9d86ff3956144e629bf55f4d657a2a7df15ffe653eb00d9176"
 dependencies = [
  "backtrace-on-stack-overflow",
 ]
 
 [[package]]
 name = "erg_compiler"
-version = "0.6.15-nightly.0"
+version = "0.6.15-nightly.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e136c552b1707b4c9d158a636ab1a3f09e2c4dee6b5d511623998080ed6021f9"
+checksum = "d7efb254c49281d259fc50c066ef98600aa39f5a5965f5b0e9fc557d84b846a6"
 dependencies = [
  "erg_common",
  "erg_parser",
@@ -196,9 +196,9 @@ dependencies = [
 
 [[package]]
 name = "erg_parser"
-version = "0.6.15-nightly.0"
+version = "0.6.15-nightly.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ad991bc363694adf11d621278109ec82d5328e2191b7f369dcb66b78f85b413a"
+checksum = "3d55758bbca26a76c4d09f4be6b95b683a91061aa56a962749854e8db0a52e71"
 dependencies = [
  "erg_common",
  "unicode-xid",
@@ -544,7 +544,7 @@ dependencies = [
 
 [[package]]
 name = "py2erg"
-version = "0.0.31"
+version = "0.0.32"
 dependencies = [
  "erg_common",
  "erg_compiler",
@@ -554,7 +554,7 @@ dependencies = [
 
 [[package]]
 name = "pylyzer"
-version = "0.0.31"
+version = "0.0.32"
 dependencies = [
  "els",
  "erg_common",
diff --git a/Cargo.toml b/Cargo.toml
index c2ad452..f5188f3 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -15,16 +15,16 @@ members = [
 ]
 
 [workspace.package]
-version = "0.0.31"
+version = "0.0.32"
 authors = ["Shunsuke Shibayama <sbym1346@gmail.com>"]
 license = "MIT OR Apache-2.0"
 edition = "2021"
 repository = "https://github.com/mtshiba/pylyzer"
 
 [workspace.dependencies]
-erg_common = { version = "0.6.15-nightly.0", features = ["py_compat", "els"] }
-erg_compiler = { version = "0.6.15-nightly.0", features = ["py_compat", "els"] }
-els = { version = "0.1.27-nightly.0", features = ["py_compat"] }
+erg_common = { version = "0.6.15-nightly.1", features = ["py_compat", "els"] }
+erg_compiler = { version = "0.6.15-nightly.1", features = ["py_compat", "els"] }
+els = { version = "0.1.27-nightly.1", features = ["py_compat"] }
 rustpython-parser = { git = "https://github.com/RustPython/Parser", version = "0.2.0", features = ["all-nodes-with-ranges", "location"] }
 rustpython-ast = { git = "https://github.com/RustPython/Parser", version = "0.2.0", features = ["all-nodes-with-ranges", "location"] }
 # erg_compiler = { git = "https://github.com/erg-lang/erg", branch = "main", features = ["py_compat", "els"] }
@@ -47,7 +47,7 @@ erg_common = { workspace = true }
 els = { workspace = true }
 rustpython-parser = { workspace = true }
 rustpython-ast = { workspace = true }
-py2erg = { version = "0.0.31", path = "./crates/py2erg" }
+py2erg = { version = "0.0.32", path = "./crates/py2erg" }
 
 [lib]
 path = "src/lib.rs"
diff --git a/crates/py2erg/convert.rs b/crates/py2erg/convert.rs
index b7ac54e..a2bea81 100644
--- a/crates/py2erg/convert.rs
+++ b/crates/py2erg/convert.rs
@@ -2,7 +2,7 @@ use std::path::Path;
 
 use erg_common::config::ErgConfig;
 use erg_common::dict::Dict as HashMap;
-use erg_common::fresh::fresh_varname;
+use erg_common::fresh::FRESH_GEN;
 use erg_common::set::Set as HashSet;
 use erg_common::traits::{Locational, Stream};
 use erg_common::{log, set};
@@ -472,8 +472,8 @@ impl ASTConverter {
             ),
             py_ast::Expr::Tuple(expr) => {
                 let loc = expr.location();
-                let tmp = fresh_varname();
-                let tmp_name = VarName::from_str_and_line((&tmp).into(), expr.location().row.get());
+                let tmp = FRESH_GEN.fresh_varname();
+                let tmp_name = VarName::from_str_and_line(tmp, expr.location().row.get());
                 let tmp_expr = Expr::Accessor(Accessor::Ident(Identifier::new(
                     VisModifierSpec::Public(DOT),
                     tmp_name.clone(),
@@ -1665,11 +1665,9 @@ impl ASTConverter {
                             Expr::ReDef(adef)
                         }
                         py_ast::Expr::Tuple(tuple) => {
-                            let tmp = fresh_varname();
-                            let tmp_name = VarName::from_str_and_line(
-                                (&tmp).into(),
-                                tuple.location().row.get(),
-                            );
+                            let tmp = FRESH_GEN.fresh_varname();
+                            let tmp_name =
+                                VarName::from_str_and_line(tmp, tuple.location().row.get());
                             let tmp_ident = Identifier::new(VisModifierSpec::Public(DOT), tmp_name);
                             let tmp_expr = Expr::Accessor(Accessor::Ident(tmp_ident.clone()));
                             let sig = Signature::Var(VarSignature::new(