diff --git a/gallery_dl/extractor/instagram.py b/gallery_dl/extractor/instagram.py
index 422c865f..dd1272f4 100644
--- a/gallery_dl/extractor/instagram.py
+++ b/gallery_dl/extractor/instagram.py
@@ -14,7 +14,6 @@ from .. import text, util, exception
 from ..cache import cache, memcache
 import itertools
 import binascii
-import json
 import re
 
 BASE_PATTERN = r"(?:https?://)?(?:www\.)?instagram\.com"
@@ -913,7 +912,7 @@ class InstagramGraphqlAPI():
         self.user_collection = self.user_saved = self.reels_media = \
             self.highlights_media = self.guide = self.guide_media = \
             self._unsupported
-        self._json_dumps = json.JSONEncoder(separators=(",", ":")).encode
+        self._json_dumps = util.json_dumps
 
         api = InstagramRestAPI(extractor)
         self.user_by_name = api.user_by_name
diff --git a/gallery_dl/extractor/twitter.py b/gallery_dl/extractor/twitter.py
index d4ec343c..9c9d5052 100644
--- a/gallery_dl/extractor/twitter.py
+++ b/gallery_dl/extractor/twitter.py
@@ -13,7 +13,6 @@ from .. import text, util, exception
 from ..cache import cache, memcache
 import itertools
 import random
-import json
 import re
 
 BASE_PATTERN = (r"(?:https?://)?(?:www\.|mobile\.)?"
@@ -1034,7 +1033,7 @@ class TwitterAPI():
 
         self.root = "https://x.com/i/api"
         self._nsfw_warning = True
-        self._json_dumps = json.JSONEncoder(separators=(",", ":")).encode
+        self._json_dumps = util.json_dumps
 
         cookies = extractor.cookies
         cookies_domain = extractor.cookies_domain
diff --git a/gallery_dl/util.py b/gallery_dl/util.py
index 128f48b7..d5bc1717 100644
--- a/gallery_dl/util.py
+++ b/gallery_dl/util.py
@@ -253,7 +253,11 @@ def json_default(obj):
 
 
 json_loads = json._default_decoder.decode
-json_dumps = json.JSONEncoder(default=json_default).encode
+json_dumps = json.JSONEncoder(
+    check_circular=False,
+    separators=(",", ":"),
+    default=json_default,
+).encode
 
 
 def dump_json(obj, fp=sys.stdout, ensure_ascii=True, indent=4):
diff --git a/test/test_formatter.py b/test/test_formatter.py
index f1d752da..c0b504da 100644
--- a/test/test_formatter.py
+++ b/test/test_formatter.py
@@ -64,7 +64,7 @@ class TestFormatter(unittest.TestCase):
         self._run_test("{t!d}", datetime.datetime(2010, 1, 1))
         self._run_test("{t!d:%Y-%m-%d}", "2010-01-01")
         self._run_test("{dt!T}", "1262304000")
-        self._run_test("{l!j}", '["a", "b", "c"]')
+        self._run_test("{l!j}", '["a","b","c"]')
         self._run_test("{dt!j}", '"2010-01-01 00:00:00"')
         self._run_test("{a!g}", "hello-world")
         self._run_test("{a!L}", 11)