diff --git a/timezones/test_timezones.py b/timezones/test_timezones.py
index 912a97f..be62f7b 100644
--- a/timezones/test_timezones.py
+++ b/timezones/test_timezones.py
@@ -1,5 +1,3 @@
-import os.path
-
 import pytest
 
 from . import _defs, tz_rendering, tz_utils, zones
@@ -63,7 +61,7 @@ def test_valid_offset(offset_str, tzname, verbose_name):
     assert offset_str == expected_offset, f"Invalid offset for {tzname}"
 
     # 3. Test verbose name
-    assert verbose_name.startswith("(GMT%s) " % expected_offset)
+    assert verbose_name.startswith(f"(GMT{expected_offset}) ")
 
 
 def test_get_timezones_json():
diff --git a/timezones/tz_rendering.py b/timezones/tz_rendering.py
index 5fc457d..fd76c4e 100644
--- a/timezones/tz_rendering.py
+++ b/timezones/tz_rendering.py
@@ -70,12 +70,12 @@ def render_option_disabled():
     if select_id:
         select_elm = f'<select name="{select_name}" id="{select_id}">'
     else:
-        select_elm = '<select name="%s">' % select_name
+        select_elm = f'<select name="{select_name}">'
 
     result = [select_elm]
 
     if first_entry:
-        result.append('<option value="">%s</option>' % first_entry)
+        result.append(f'<option value="">{first_entry}</option>')
         result.append(render_option_disabled())
 
     if force_current_selected and current_selected: