diff --git a/src/calibre/db/categories.py b/src/calibre/db/categories.py
index 67fb18b841..deac2094cc 100644
--- a/src/calibre/db/categories.py
+++ b/src/calibre/db/categories.py
@@ -118,12 +118,14 @@ def clean_user_categories(dbcache):
 numeric_collation = prefs['numeric_collation']
 
 
-def first_digit(x):
-    c = icu_upper(x.sort or x.name or ' ')[0]
+def sort_key_for_name_and_first_letter(x):
+    v1 = icu_upper(x.sort or x.name)
+    v2 = v1 or ' '
     # 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
-    return c if numeric_collation and c.isdigit() else '9999999999'
-
+    c = v2[0]
+    return (c if numeric_collation and c.isdigit() else '9999999999',
+            collation_order(v2), sort_key(v1))
 
 category_sort_keys = {True:{}, False: {}}
 category_sort_keys[True]['popularity'] = category_sort_keys[False]['popularity'] = \
@@ -131,7 +133,7 @@ category_sort_keys[True]['popularity'] = category_sort_keys[False]['popularity']
 category_sort_keys[True]['rating'] = category_sort_keys[False]['rating'] = \
     lambda x:(-getattr(x, 'avg_rating', 0.0), sort_key(x.sort or x.name))
 category_sort_keys[True]['name'] = \
-    lambda x:(first_digit(x), collation_order(icu_upper(x.sort or x.name or ' ')), sort_key(x.sort or x.name))
+    sort_key_for_name_and_first_letter
 category_sort_keys[False]['name'] = \
     lambda x:sort_key(x.sort or x.name)