diff --git a/geomagio/api/ws/algorithms.py b/geomagio/api/ws/algorithms.py
index 69ff63d2ce0e849ccfdfeb93f595cd10e138b540..0e2d51cb9fe9bb1546fc7bbea2cb77d09472d09a 100644
--- a/geomagio/api/ws/algorithms.py
+++ b/geomagio/api/ws/algorithms.py
@@ -22,4 +22,6 @@ def get_dbdt(
     timeseries = dbdt.process(raw)
     elements = [f"{element}_DT" for element in query.elements]
     # output response
-    return format_timeseries(timeseries=timeseries, format=format, elements=elements)
+    return format_timeseries(
+        timeseries=timeseries, format=query.format, elements=elements
+    )