diff --git a/spaceweather_processing/app.py b/spaceweather_processing/app.py
index f5b09e64318d7d794a1b6e205f212d884915ea83..b8c3a221cde94fd66f386b317be8c5b6067a27b4 100644
--- a/spaceweather_processing/app.py
+++ b/spaceweather_processing/app.py
@@ -138,7 +138,7 @@ class DataProductDB:
         if sort:
             if sort.startswith('-'):
                 direction = -1
-                sort = sort[1:]
+                sort = sort.lstrip('-')
             else:
                 direction = 1