diff --git a/swh/lister/core/indexing_lister.py b/swh/lister/core/indexing_lister.py
--- a/swh/lister/core/indexing_lister.py
+++ b/swh/lister/core/indexing_lister.py
@@ -103,7 +103,7 @@
                 declare approximately equal-sized ranges of existing
                 repos
         """
-        n = self.db_num_entries()
+        n = max(self.db_num_entries(), 10)
 
         partitions = []
         partition_size = min(partition_size, n)