diff --git a/admin/delete.php b/admin/delete.php
index 69cd860..b5be919 100644
--- a/admin/delete.php
+++ b/admin/delete.php
@@ -1,6 +1,6 @@
 <?php
 
-$id = $_GET["id"];
+$id = (int)$_GET["id"];
 
 if ($id === null) {
     exit();
diff --git a/admin/respond.php b/admin/respond.php
index 16b20b0..aed9d20 100644
--- a/admin/respond.php
+++ b/admin/respond.php
@@ -1,6 +1,6 @@
 <?php
 
-$id = $_GET["id"];
+$id = (int)$_GET["id"];
 
 if ($id === null) {
     exit();
diff --git a/fetch.php b/fetch.php
index 44fa25e..c3b043d 100644
--- a/fetch.php
+++ b/fetch.php
@@ -2,7 +2,7 @@
 
 include 'config.php';
 
-$id = $_GET["id"];
+$id = (int)$_GET["id"];
 
 if ($id === null) {
     exit();