diff --git a/src/calibre/db/categories.py b/src/calibre/db/categories.py
index b9de1316f9..552ec68523 100644
--- a/src/calibre/db/categories.py
+++ b/src/calibre/db/categories.py
@@ -116,8 +116,9 @@ def clean_user_categories(dbcache):
 
 
 numeric_collation = tweaks['numeric_collation']
+
+
 def first_digit(x):
-    global numeric_collation
     c = icu_upper(x.sort or x.name or ' ')[0]
     # The idea is that '9999999999' is larger than any digit so all digits
     # will sort in front. Non-digits will sort according to their ICU first letter
diff --git a/src/calibre/utils/icu_test.py b/src/calibre/utils/icu_test.py
index d40a720b91..ec407537d8 100644
--- a/src/calibre/utils/icu_test.py
+++ b/src/calibre/utils/icu_test.py
@@ -116,7 +116,6 @@ class TestICU(unittest.TestCase):
 
     def test_collation_order(self):
         'Testing collation ordering'
-        from calibre.utils.icu import collation_order
         for group in [
             (self.ae,  ('Šaa', 'Smith', 'Solženicyn', 'Štepánek')),
             (self.ae,  ('11', '011')),