diff --git a/test/test_jsinterp.py b/test/test_jsinterp.py
index 4da8ae3536..df273b41f0 100644
--- a/test/test_jsinterp.py
+++ b/test/test_jsinterp.py
@@ -330,6 +330,7 @@ class TestJSInterpreter(unittest.TestCase):
         self._test('function f() { let a = {m1: 42, m2: 0 }; return [a["m1"], a.m2]; }', [42, 0])
         self._test('function f() { let a; return a?.qq; }', JS_Undefined)
         self._test('function f() { let a = {m1: 42, m2: 0 }; return a?.qq; }', JS_Undefined)
+        self._test('function f() { let a = {"1": 123}; return a[1]; }', 123)
 
     def test_regex(self):
         self._test('function f() { let a=/,,[/,913,/](,)}/; }', None)
diff --git a/yt_dlp/jsinterp.py b/yt_dlp/jsinterp.py
index 6ca2b16375..362e5a4380 100644
--- a/yt_dlp/jsinterp.py
+++ b/yt_dlp/jsinterp.py
@@ -385,7 +385,7 @@ class JSInterpreter:
         if idx == 'length':
             return len(obj)
         try:
-            return obj[int(idx)] if isinstance(obj, list) else obj[idx]
+            return obj[int(idx)] if isinstance(obj, list) else obj[str(idx)]
         except Exception as e:
             if allow_undefined:
                 return JS_Undefined