diff --git a/functions.php b/functions.php
index c831a83a..a158ee13 100644
--- a/functions.php
+++ b/functions.php
@@ -850,7 +850,7 @@ function calculateAccountBalance($mysqli, $account_id) {
     $sql_account = mysqli_query($mysqli, "SELECT * FROM accounts LEFT JOIN account_types ON accounts.account_type = account_types.account_type_id WHERE account_archived_at  IS NULL AND account_id = $account_id ORDER BY account_name ASC; ");
     $row = mysqli_fetch_array($sql_account);
     $opening_balance = floatval($row['opening_balance']);
-    $account_id = $row['account_id'];
+    $account_id = intval($row['account_id']);
     
     $sql_payments = mysqli_query($mysqli, "SELECT SUM(payment_amount) AS total_payments FROM payments WHERE payment_account_id = $account_id");
     $row = mysqli_fetch_array($sql_payments);
@@ -877,7 +877,7 @@ function calculateInvoiceBalance($mysqli, $invoice_id) {
     $sql_invoice = mysqli_query($mysqli, "SELECT * FROM invoices WHERE invoice_id = $invoice_id");
     $row = mysqli_fetch_array($sql_invoice);
     $invoice_amount = floatval($row['invoice_amount']);
-    $invoice_id = $row['invoice_id'];
+    $invoice_id = intval($row['invoice_id']);
 
     $sql_payments = mysqli_query($mysqli, "SELECT SUM(payment_amount) AS total_payments FROM payments WHERE payment_invoice_id = $invoice_id");
     $row = mysqli_fetch_array($sql_payments);