diff --git a/web/analysis_service.py b/web/analysis_service.py
index db9b325f..fe44d03f 100644
--- a/web/analysis_service.py
+++ b/web/analysis_service.py
@@ -1668,6 +1668,7 @@ def _analyze(
             d_version = deb_version
             d_bias_adjustment = deb_bias_adjustment
             d_bias_samples = deb_bias_samples
+            d_quality = dict(deb_quality)
         else:
             day_m = mm_daily_raw.get(d_str, {}).copy()
             if i < len(maxtemps) and maxtemps[i] is not None: