diff --git a/app/api/services/base_service.py b/app/api/services/base_service.py
index ae9747d..b3a657e 100644
--- a/app/api/services/base_service.py
+++ b/app/api/services/base_service.py
@@ -102,7 +102,7 @@ class BaseService:
         upfront_payment = sum(upfront_fees)
 
           # Repayment amount: (principal + only those fees not due immediately i.e due_days != 0)
-        repayment_amount = amount + sum(postpaid_fees) * tenor
+        repayment_amount = amount + (sum(postpaid_fees) * tenor)
 
         # Total amount: (upfront_payment + repayment_amount)
         total_amount = upfront_payment + repayment_amount