diff --git a/rangefilter/filter.py b/rangefilter/filter.py
index 120f2f6..91015db 100644
--- a/rangefilter/filter.py
+++ b/rangefilter/filter.py
@@ -54,7 +54,10 @@ def make_dt_aware(value, timezone):
 
     def choices(self, cl):
         yield {
-            'system_name': slugify(self.title),
+            # slugify converts any non-unicode characters to empty characters
+            # but system_name is required, if title converts to empty string use id
+            # https://github.com/silentsokolov/django-admin-rangefilter/issues/18
+            'system_name': slugify(self.title) if slugify(self.title) else id(self.title),
             'query_string': cl.get_query_string(
                 {}, remove=self._get_expected_fields()
             )