diff --git a/laborious/activities/api.py b/laborious/activities/api.py
index d91b0e3..0e4114f 100644
--- a/laborious/activities/api.py
+++ b/laborious/activities/api.py
@@ -279,7 +279,7 @@ class API(SientiaMonitoring):
                 web_ids=confidence_tags,
                 value={
                     'Timestamp': data.head(1)['timestamp'].values[0],
-                    'Value': confidence_value,
+                    'Value': float(confidence_value),
                 },
                 metadata=metadata,
             )