diff --git a/crates/oxc_codegen/src/gen.rs b/crates/oxc_codegen/src/gen.rs
index dec059b0737d8..a586665c33996 100644
--- a/crates/oxc_codegen/src/gen.rs
+++ b/crates/oxc_codegen/src/gen.rs
@@ -1324,9 +1324,9 @@ impl GenExpr for NumericLiteral<'_> {
 
 impl GenExpr for BigIntLiteral<'_> {
     fn gen_expr(&self, p: &mut Codegen, precedence: Precedence, _ctx: Context) {
-        let raw = self.raw.as_str().cow_replace('_', "");
-
+        p.print_space_before_identifier();
         p.add_source_mapping(self.span);
+        let raw = self.raw.as_str().cow_replace('_', "");
         if !raw.starts_with('-') {
             p.print_str(&raw);
         } else if precedence >= Precedence::Prefix {
diff --git a/crates/oxc_codegen/tests/integration/unit.rs b/crates/oxc_codegen/tests/integration/unit.rs
index 7a458ff6e747e..7a5a060e9fd0f 100644
--- a/crates/oxc_codegen/tests/integration/unit.rs
+++ b/crates/oxc_codegen/tests/integration/unit.rs
@@ -402,6 +402,9 @@ fn big_int() {
     test("0xfabn", "0xfabn;\n");
     test("0xaef_en;", "0xaefen;\n");
     test("0xaefen;", "0xaefen;\n");
+
+    test("return 1n", "return 1n;\n");
+    test_minify("return 1n", "return 1n;");
 }
 
 #[test]