diff --git a/crates/oxc_ecmascript/src/to_string.rs b/crates/oxc_ecmascript/src/to_string.rs
index c2beb2fea1f84..a7d46981589ee 100644
--- a/crates/oxc_ecmascript/src/to_string.rs
+++ b/crates/oxc_ecmascript/src/to_string.rs
@@ -89,10 +89,10 @@ impl<'a> ToJsString<'a> for NumericLiteral<'a> {
     }
 }
 
+/// <https://tc39.es/ecma262/multipage/numbers-and-dates.html#sec-bigint.prototype.tostring>
 impl<'a> ToJsString<'a> for BigIntLiteral<'a> {
     fn to_js_string(&self) -> Option<Cow<'a, str>> {
-        // FIXME: to js bigint string
-        Some(Cow::Owned(self.raw.to_string()))
+        self.base.is_base_10().then(|| Cow::Owned(self.raw.trim_end_matches('n').to_string()))
     }
 }
 
diff --git a/crates/oxc_minifier/src/ast_passes/peephole_replace_known_methods.rs b/crates/oxc_minifier/src/ast_passes/peephole_replace_known_methods.rs
index 432cad046878c..435534cbf3ec9 100644
--- a/crates/oxc_minifier/src/ast_passes/peephole_replace_known_methods.rs
+++ b/crates/oxc_minifier/src/ast_passes/peephole_replace_known_methods.rs
@@ -314,9 +314,16 @@ impl<'a> PeepholeReplaceKnownMethods {
                 }
                 Some(ctx.ast.expression_string_literal(ce.span, Self::format_radix(i, radix), None))
             }
-            e if e.is_literal() && args.is_empty() => {
+            // `null` returns type errors
+            Expression::BooleanLiteral(_)
+            | Expression::NumericLiteral(_)
+            | Expression::BigIntLiteral(_)
+            | Expression::RegExpLiteral(_)
+            | Expression::StringLiteral(_)
+                if args.is_empty() =>
+            {
                 use oxc_ecmascript::ToJsString;
-                e.to_js_string().map(|s| ctx.ast.expression_string_literal(ce.span, s, None))
+                object.to_js_string().map(|s| ctx.ast.expression_string_literal(ce.span, s, None))
             }
             _ => None,
         }
@@ -1209,7 +1216,10 @@ mod test {
         test("123 .toString()", "'123';");
         test("NaN.toString()", "'NaN';");
         test("Infinity.toString()", "'Infinity';");
-        // test("/a\\\\b/ig.toString()", "'/a\\\\\\\\b/ig';");
+        test("1n.toString()", "'1'");
+        test_same("254n.toString(16);"); // unimplemented
+                                         // test("/a\\\\b/ig.toString()", "'/a\\\\\\\\b/ig';");
+        test_same("null.toString()"); // type error
 
         test("100 .toString(0)", "100 .toString(0)");
         test("100 .toString(1)", "100 .toString(1)");
diff --git a/crates/oxc_minifier/tests/ecmascript/array_join.rs b/crates/oxc_minifier/tests/ecmascript/array_join.rs
index a8da47a089167..33a4b0d370f27 100644
--- a/crates/oxc_minifier/tests/ecmascript/array_join.rs
+++ b/crates/oxc_minifier/tests/ecmascript/array_join.rs
@@ -33,9 +33,9 @@ fn test() {
         ast.alloc(ast.object_expression(SPAN, ast.vec(), None)),
     ));
     let joined = array2.array_join(Some("_"));
-    assert_eq!(joined, Some("__42_foo_true_42n_,,42,foo,true,42n_[object Object]".to_string()));
+    assert_eq!(joined, Some("__42_foo_true_42_,,42,foo,true,42_[object Object]".to_string()));
 
     let joined2 = array2.array_join(None);
     // By default, in `Array.prototype.toString`, the separator is a comma. However, in `Array.prototype.join`, the separator is none if not given.
-    assert_eq!(joined2, Some(",,42,foo,true,42n,,,42,foo,true,42n,[object Object]".to_string()));
+    assert_eq!(joined2, Some(",,42,foo,true,42,,,42,foo,true,42,[object Object]".to_string()));
 }