diff --git a/src/lagrangian/intermediate/parcels/Templates/ReactingMultiphaseParcel/ReactingMultiphaseParcel.C b/src/lagrangian/intermediate/parcels/Templates/ReactingMultiphaseParcel/ReactingMultiphaseParcel.C
index 84942b0349..461ec5b285 100644
--- a/src/lagrangian/intermediate/parcels/Templates/ReactingMultiphaseParcel/ReactingMultiphaseParcel.C
+++ b/src/lagrangian/intermediate/parcels/Templates/ReactingMultiphaseParcel/ReactingMultiphaseParcel.C
@@ -636,7 +636,7 @@ void Foam::ReactingMultiphaseParcel<ParcelType>::calcSurfaceReactions
        *(sum(dMassSRGas) + sum(dMassSRLiquid) + sum(dMassSRSolid))
     );
 
-    const scalar xsi = min(T/5000.0, 1.0);
+    const scalar xsi = min(T/td.cloud().constProps().TMax(), 1.0);
     const scalar coeff =
         (1.0 - xsi*xsi)*td.cloud().constProps().hRetentionCoeff();