diff --git a/src/pretix/base/templatetags/rich_text.py b/src/pretix/base/templatetags/rich_text.py
index 2e85f8923a..cedae3069c 100644
--- a/src/pretix/base/templatetags/rich_text.py
+++ b/src/pretix/base/templatetags/rich_text.py
@@ -100,7 +100,7 @@ def truelink_callback(attrs, new=False):
 
         <a href="https://maps.google.com/location/foo">https://maps.google.com</a>
     """
-    text = re.sub('[^a-zA-Z0-9.-/_]', '', attrs.get('_text'))  # clean up link text
+    text = re.sub(r'[^a-zA-Z0-9.\-/_]', '', attrs.get('_text'))  # clean up link text
     href_url = urllib.parse.urlparse(attrs[None, 'href'])
     if URL_RE.match(text) and href_url.scheme not in ('tel', 'mailto'):
         # link text looks like a url
diff --git a/src/tests/base/test_rich_text.py b/src/tests/base/test_rich_text.py
index 4bd034bb5e..f6c63ba138 100644
--- a/src/tests/base/test_rich_text.py
+++ b/src/tests/base/test_rich_text.py
@@ -17,6 +17,10 @@ from pretix.base.templatetags.rich_text import (
     ("mail@example.org",
      '<a href="mailto:mail@example.org">mail@example.org</a>'),
     # Test truelink_callback
+    ('evilsite.com',
+     '<a href="http://evilsite.com" rel="noopener" target="_blank">evilsite.com</a>'),
+    ('cool-example.eu',
+     '<a href="http://cool-example.eu" rel="noopener" target="_blank">cool-example.eu</a>'),
     ('<a href="https://evilsite.com">Evil Site</a>',
      '<a href="https://evilsite.com" rel="noopener" target="_blank">Evil Site</a>'),
     ('<a href="https://evilsite.com">evilsite.com</a>',