diff --git a/compiler/erg_compiler/compile.rs b/compiler/erg_compiler/compile.rs
index 9fcad1c2..778868f1 100644
--- a/compiler/erg_compiler/compile.rs
+++ b/compiler/erg_compiler/compile.rs
@@ -11,8 +11,9 @@ use crate::ty::codeobj::CodeObj;
 
 use crate::build_hir::HIRBuilder;
 use crate::codegen::CodeGenerator;
+use crate::desugar_hir::HIRDesugarer;
 use crate::error::{CompileError, CompileErrors};
-use crate::hir::Expr;
+use crate::hir::{Expr, HIR};
 use crate::link::Linker;
 use crate::mod_cache::SharedModuleCache;
 
@@ -170,9 +171,7 @@ impl Compiler {
 
     pub fn compile(&mut self, src: String, mode: &str) -> Result<CodeObj, CompileErrors> {
         log!(info "the compiling process has started.");
-        let hir = self.builder.build(src, mode).map_err(|(_, errs)| errs)?;
-        let linker = Linker::new(&self.cfg, &self.mod_cache);
-        let hir = linker.link(hir);
+        let hir = self.build_link_desugar(src, mode)?;
         let codeobj = self.code_generator.emit(hir);
         log!(info "code object:\n{}", codeobj.code_info());
         log!(info "the compiling process has completed");
@@ -185,13 +184,18 @@ impl Compiler {
         mode: &str,
     ) -> Result<(CodeObj, Option<Expr>), CompileErrors> {
         log!(info "the compiling process has started.");
-        let hir = self.builder.build(src, mode).map_err(|(_, errs)| errs)?;
+        let hir = self.build_link_desugar(src, mode)?;
         let last = hir.module.last().cloned();
-        let linker = Linker::new(&self.cfg, &self.mod_cache);
-        let hir = linker.link(hir);
         let codeobj = self.code_generator.emit(hir);
         log!(info "code object:\n{}", codeobj.code_info());
         log!(info "the compiling process has completed");
         Ok((codeobj, last))
     }
+
+    fn build_link_desugar(&mut self, src: String, mode: &str) -> Result<HIR, CompileErrors> {
+        let hir = self.builder.build(src, mode).map_err(|(_, errs)| errs)?;
+        let linker = Linker::new(&self.cfg, &self.mod_cache);
+        let hir = linker.link(hir);
+        Ok(HIRDesugarer::desugar(hir))
+    }
 }
diff --git a/compiler/erg_compiler/desugar_hir.rs b/compiler/erg_compiler/desugar_hir.rs
index 2183ae7f..df5ca175 100644
--- a/compiler/erg_compiler/desugar_hir.rs
+++ b/compiler/erg_compiler/desugar_hir.rs
@@ -1,6 +1,12 @@
+use crate::hir::HIR;
+
 pub struct HIRDesugarer {}
 
 impl HIRDesugarer {
+    pub fn desugar(hir: HIR) -> HIR {
+        hir
+    }
+
     // C = Class ...
     // C.
     //     _Self = C
@@ -9,7 +15,9 @@ impl HIRDesugarer {
     // ↓
     // class C:
     //     def _Self(): return C
-    //     def a(): return C.x
+    //     def a(): return C.x()
     //     def x(): return 1
-    fn _desugar_class_member() {}
+    fn _desugar_class_member(_hir: HIR) -> HIR {
+        _hir
+    }
 }
diff --git a/compiler/erg_parser/build_ast.rs b/compiler/erg_parser/build_ast.rs
index eae7e63e..0676e308 100644
--- a/compiler/erg_parser/build_ast.rs
+++ b/compiler/erg_parser/build_ast.rs
@@ -23,8 +23,6 @@ impl ASTBuilder {
         let module = self.runner.parse(src)?;
         let mut desugarer = Desugarer::new();
         let module = desugarer.desugar(module);
-        let mut desugarer = Desugarer::new();
-        let module = desugarer.desugar(module);
         let ast = AST::new(Str::rc(self.runner.cfg().input.filename()), module);
         Ok(ast)
     }