diff --git a/compiler/erg_parser/ast.rs b/compiler/erg_parser/ast.rs
index 2b0d12b1..af1a3e14 100644
--- a/compiler/erg_parser/ast.rs
+++ b/compiler/erg_parser/ast.rs
@@ -775,8 +775,10 @@ pub struct NormalSet {
 }
 
 impl NestedDisplay for NormalSet {
-    fn fmt_nest(&self, f: &mut fmt::Formatter<'_>, _level: usize) -> fmt::Result {
-        write!(f, "{{{}}}", self.elems)
+    fn fmt_nest(&self, f: &mut fmt::Formatter<'_>, level: usize) -> fmt::Result {
+        writeln!(f, "{{")?;
+        self.elems.fmt_nest(f, level + 1)?;
+        write!(f, "{}}}", "    ".repeat(level))
     }
 }