diff --git a/main/templatetags/cdn.py b/main/templatetags/cdn.py
index 7df5c1f71..1e0e0ce4e 100644
--- a/main/templatetags/cdn.py
+++ b/main/templatetags/cdn.py
@@ -9,24 +9,24 @@
 @register.simple_tag
 def jquery():
     version = '3.6.0'
-    filename = 'jquery-%s.min.js' % version
+    filename = f'jquery-{version}.min.js'
     link = staticfiles_storage.url(filename)
-    return mark_safe('<script type="text/javascript" src="%s"></script>' % link)
+    return mark_safe(f'<script type="text/javascript" src="{link}"></script>')
 
 
 @register.simple_tag
 def jquery_tablesorter():
     version = '2.31.0'
-    filename = 'jquery.tablesorter-%s.min.js' % version
+    filename = f'jquery.tablesorter-{version}.min.js'
     link = staticfiles_storage.url(filename)
-    return format_html('<script type="text/javascript" src="%s"></script>' % link)
+    return format_html('<script type="text/javascript" src="{link}"></script>', link=link)
 
 
 @register.simple_tag
 def d3js():
     version = '3.5.0'
-    filename = 'd3-%s.min.js' % version
+    filename = f'd3-{version}.min.js'
     link = staticfiles_storage.url(filename)
-    return format_html('<script type="text/javascript" src="%s"></script>' % link)
+    return format_html('<script type="text/javascript" src="{link}"></script>', link=link)
 
 # vim: set ts=4 sw=4 et:
diff --git a/main/templatetags/flags.py b/main/templatetags/flags.py
index 54115d357..0da58f636 100644
--- a/main/templatetags/flags.py
+++ b/main/templatetags/flags.py
@@ -8,8 +8,11 @@
 def country_flag(country):
     if not country:
         return ''
-    return format_html('<span class="fam-flag fam-flag-%s" title="%s"></span> ' % (
-        str(country.code).lower(), str(country.name)))
+    return format_html(
+        '<span class="fam-flag fam-flag-{country_code}" title="{country_name}"></span> ',
+        country_code=str(country.code).lower(),
+        country_name=str(country.name),
+    )
 
 
 # vim: set ts=4 sw=4 et:
diff --git a/main/templatetags/pgp.py b/main/templatetags/pgp.py
index 7eb8f456c..4b7e57901 100644
--- a/main/templatetags/pgp.py
+++ b/main/templatetags/pgp.py
@@ -56,8 +56,10 @@ def pgp_key_link(key_id, link_text=None):
                                                                                             key_id)
     if link_text is None:
         link_text = '0x%s' % key_id[-8:]
-    values = (url, format_key(key_id), link_text)
-    return format_html('<a href="%s" title="PGP key search for %s">%s</a>' % values)
+    return format_html('<a href="{url}" title="PGP key search for {key}">{content}</a>',
+                       url=url,
+                       key=format_key(key_id),
+                       content=link_text)
 
 
 @register.simple_tag
diff --git a/packages/templatetags/package_extras.py b/packages/templatetags/package_extras.py
index 6115aec99..92a411748 100644
--- a/packages/templatetags/package_extras.py
+++ b/packages/templatetags/package_extras.py
@@ -43,8 +43,8 @@ def pkg_details_link(pkg, link_title=None, honor_flagged=False):
     link_content = link_title
     if honor_flagged and pkg.flag_date:
         link_content = '<span class="flagged">%s</span>' % link_title
-    link = '<a href="%s" title="View package details for %s">%s</a>'
-    return format_html(link % (pkg.get_absolute_url(), pkg.pkgname, link_content))
+    link = '<a href="{link}" title="View package details for {pkgname}">{content}</a>'
+    return format_html(link, link=pkg.get_absolute_url(), pkgname=pkg.pkgname, content=link_content)
 
 
 # vim: set ts=4 sw=4 et:
diff --git a/settings.py b/settings.py
index 928e83f5c..8f9eb2354 100644
--- a/settings.py
+++ b/settings.py
@@ -272,4 +272,10 @@
 
     INSTALLED_APPS = [*list(INSTALLED_APPS), 'django_prometheus']
 
+# Assume all URLField will be HTTPS if not specified.
+# NOTE: this can be removed once we bump Django to 6.x
+# where `https` becomes the default.
+FORMS_URLFIELD_ASSUME_HTTPS = True
+
+
 # vim: set ts=4 sw=4 et:
diff --git a/todolists/templatetags/todolists.py b/todolists/templatetags/todolists.py
index a54a9b82e..9734ac78a 100644
--- a/todolists/templatetags/todolists.py
+++ b/todolists/templatetags/todolists.py
@@ -13,8 +13,9 @@ def todopkg_details_link(todopkg):
     pkg = todopkg.pkg
     if not pkg:
         return todopkg.pkgname
-    link = '<a href="%s" title="View package details for %s">%s</a>'
+    link = '<a href={url}s" title="View package details for {pkgname}">{pkgname}</a>'
     url = pkg_absolute_url(todopkg.repo, todopkg.arch, pkg.pkgname)
-    return format_html(link % (url, pkg.pkgname, pkg.pkgname))
+    return format_html(link, url=url, pkgname=pkg.pkgname)
+
 
 # vim: set ts=4 sw=4 et: