diff --git a/src/client/services/prepareData.ts b/src/client/services/prepareData.ts
index 4ea7ea6..f53cf48 100644
--- a/src/client/services/prepareData.ts
+++ b/src/client/services/prepareData.ts
@@ -537,7 +537,7 @@ export const prepareCalculationData = ({
     if (evo_coefficient) {
       preparedValues.nsBonus =
         (evo_coefficient.evo_sot_coefficient || 0) *
-        insuranceNSRow?.insCost?.value;
+        (insuranceNSRow?.insCost?.value || 0);
     }
   }