diff --git a/tradein-mvp/backend/app/services/estimator.py b/tradein-mvp/backend/app/services/estimator.py
index dead7bd5..e3b74d72 100644
--- a/tradein-mvp/backend/app/services/estimator.py
+++ b/tradein-mvp/backend/app/services/estimator.py
@@ -876,7 +876,11 @@ async def estimate_quality(
                 rent_price_rub=int(cian_val.rent_price_rub) if cian_val.rent_price_rub else None,
                 chart=list(cian_val.chart or []),
                 chart_change_pct=cian_val.chart_change_pct,
-                chart_change_direction=cian_val.chart_change_direction,
+                chart_change_direction=(
+                    cian_val.chart_change_direction
+                    if cian_val.chart_change_direction in {"increase", "decrease", "neutral"}
+                    else None
+                ),
             )
             if cian_val is not None
             else None