diff --git a/guix-data-service/model/derivation.scm b/guix-data-service/model/derivation.scm
index d61c6e5..f037b50 100644
--- a/guix-data-service/model/derivation.scm
+++ b/guix-data-service/model/derivation.scm
@@ -1604,7 +1604,7 @@ LIMIT $1"
             (map (lambda (result)
                    (string->number (car result)))
                  (exec-query conn (insert-into-derivations chunk))))
-          (chunk derivations 5000))))
+          (chunk derivations 500))))
 
     (simple-format
      #t "debug: insert-missing-derivations: updating hash table\n")
diff --git a/guix-data-service/model/utils.scm b/guix-data-service/model/utils.scm
index 093161a..f40174a 100644
--- a/guix-data-service/model/utils.scm
+++ b/guix-data-service/model/utils.scm
@@ -388,7 +388,7 @@ WHERE table_name = $1"
                         (string->number (first result)))
                       (exec-query conn
                                   (insert-sql missing-entries-chunk))))
-               (chunk missing-entries 5000))))
+               (chunk missing-entries 3000))))
 
          (new-entries-lookup-vhash
           (two-lists->vhash missing-entries