diff --git a/blocking.py b/blocking.py
index f9d3a8807..0b745cea3 100644
--- a/blocking.py
+++ b/blocking.py
@@ -12,6 +12,7 @@ import json
 import time
 from session import get_json_valid
 from session import create_session
+from utils import string_contains
 from utils import date_from_string_format
 from utils import date_utcnow
 from utils import remove_eol
@@ -1998,10 +1999,7 @@ def save_block_federated_endpoints(base_dir: str,
         if not endpoint:
             continue
         if '.' not in endpoint or \
-           ' ' in endpoint or \
-           '<' in endpoint or \
-           ',' in endpoint or \
-           ';' in endpoint:
+           string_contains(endpoint, (' ', '<', ',', ';')):
             continue
         if endpoint.startswith('@'):
             endpoint = endpoint[1:]
diff --git a/content.py b/content.py
index befb8b893..38912abfd 100644
--- a/content.py
+++ b/content.py
@@ -15,6 +15,7 @@ import email.parser
 import urllib.parse
 from shutil import copyfile
 from dateutil.parser import parse
+from utils import string_contains
 from utils import string_ends_with
 from utils import is_account_dir
 from utils import get_url_from_post
@@ -263,9 +264,7 @@ def dangerous_css(filename: str, allow_local_network_access: bool) -> bool:
             if ctr > 0:
                 if ')' in url_str:
                     url_str = url_str.split(')')[0]
-                    if 'http' in url_str or \
-                       'ipfs' in url_str or \
-                       'ipns' in url_str:
+                    if string_contains(url_str, ('http', 'ipfs', 'ipns')):
                         print('ERROR: non-local web link in CSS ' +
                               filename)
                         return True
diff --git a/daemon.py b/daemon.py
index 44f40fec2..60407fa6e 100644
--- a/daemon.py
+++ b/daemon.py
@@ -50,6 +50,7 @@ from shares import expire_shares
 from categories import load_city_hashtags
 from categories import update_hashtag_categories
 from languages import load_default_post_languages
+from utils import string_contains
 from utils import check_bad_path
 from utils import acct_handle_dir
 from utils import load_reverse_timeline
@@ -310,9 +311,9 @@ class PubServer(BaseHTTPRequestHandler):
         file_length = -1
         last_modified_time_str = None
 
-        if '/media/' in self.path or \
-           '/accounts/avatars/' in self.path or \
-           '/accounts/headers/' in self.path:
+        if string_contains(self.path,
+                           ('/media/', '/accounts/avatars/',
+                            '/accounts/headers/')):
             if is_image_file(self.path) or \
                path_is_video(self.path) or \
                path_is_audio(self.path):