diff --git a/test/test_utils.py b/test/test_utils.py
index c2d1e4fb1..925a21d34 100644
--- a/test/test_utils.py
+++ b/test/test_utils.py
@@ -937,6 +937,28 @@ class TestUtil(unittest.TestCase):
         self.assertEqual(d['x'], 1)
         self.assertEqual(d['y'], 'a')
 
+        # Just drop ! prefix for now though this results in a wrong value
+        on = js_to_json('''{
+            a: !0,
+            b: !1,
+            c: !!0,
+            d: !!42.42,
+            e: !!![],
+            f: !"abc",
+            g: !"",
+            !42: 42
+        }''')
+        self.assertEqual(json.loads(on), {
+            'a': 0,
+            'b': 1,
+            'c': 0,
+            'd': 42.42,
+            'e': [],
+            'f': "abc",
+            'g': "",
+            '42': 42
+        })
+
         on = js_to_json('["abc", "def",]')
         self.assertEqual(json.loads(on), ['abc', 'def'])
 
diff --git a/youtube_dl/utils.py b/youtube_dl/utils.py
index 737e2810e..321f903ab 100644
--- a/youtube_dl/utils.py
+++ b/youtube_dl/utils.py
@@ -4078,7 +4078,7 @@ def js_to_json(code):
         v = m.group(0)
         if v in ('true', 'false', 'null'):
             return v
-        elif v.startswith('/*') or v.startswith('//') or v == ',':
+        elif v.startswith('/*') or v.startswith('//') or v.startswith('!') or v == ',':
             return ""
 
         if v[0] in ("'", '"'):
@@ -4103,7 +4103,8 @@ def js_to_json(code):
         {comment}|,(?={skip}[\]}}])|
         (?:(?<![0-9])[eE]|[a-df-zA-DF-Z_])[.a-zA-Z_0-9]*|
         \b(?:0[xX][0-9a-fA-F]+|0+[0-7]+)(?:{skip}:)?|
-        [0-9]+(?={skip}:)
+        [0-9]+(?={skip}:)|
+        !+
         '''.format(comment=COMMENT_RE, skip=SKIP_RE), fix_kv, code)