diff --git a/models/AttachmentModel.php b/models/AttachmentModel.php
index c5d6ac4..0ae5783 100644
--- a/models/AttachmentModel.php
+++ b/models/AttachmentModel.php
@@ -21,7 +21,7 @@ class AttachmentModel {
                 ORDER BY a.uploaded_at DESC";
 
         $stmt = $this->conn->prepare($sql);
-        $stmt->bind_param("i", $ticketId);
+        $stmt->bind_param("s", $ticketId);
         $stmt->execute();
         $result = $stmt->get_result();
 
@@ -61,7 +61,7 @@ class AttachmentModel {
                 VALUES (?, ?, ?, ?, ?, ?)";
 
         $stmt = $this->conn->prepare($sql);
-        $stmt->bind_param("issisi", $ticketId, $filename, $originalFilename, $fileSize, $mimeType, $uploadedBy);
+        $stmt->bind_param("sssisi", $ticketId, $filename, $originalFilename, $fileSize, $mimeType, $uploadedBy);
         $result = $stmt->execute();
 
         if ($result) {
@@ -97,7 +97,7 @@ class AttachmentModel {
                 WHERE ticket_id = ?";
 
         $stmt = $this->conn->prepare($sql);
-        $stmt->bind_param("i", $ticketId);
+        $stmt->bind_param("s", $ticketId);
         $stmt->execute();
         $result = $stmt->get_result();
         $row = $result->fetch_assoc();
@@ -113,7 +113,7 @@ class AttachmentModel {
         $sql = "SELECT COUNT(*) as count FROM ticket_attachments WHERE ticket_id = ?";
 
         $stmt = $this->conn->prepare($sql);
-        $stmt->bind_param("i", $ticketId);
+        $stmt->bind_param("s", $ticketId);
         $stmt->execute();
         $result = $stmt->get_result();
         $row = $result->fetch_assoc();