diff --git a/chat_window.php b/chat_window.php
index beac355..2e43238 100644
--- a/chat_window.php
+++ b/chat_window.php
@@ -650,8 +650,9 @@ if (empty($user_id)) {
                             }
 
                             if (isValidMediaUrl(fullUrl)) {
+                                // Usar data-fullurl y dataset para evitar problemas de escapado en el onclick
                                 contentHtml = `
-                                    <a href="#" onclick="openImageModal(${JSON.stringify(fullUrl)}); return false;" title="Abrir imagen">
+                                    <a href="#" data-fullurl="${escapeHtml(fullUrl)}" onclick="openImageModal(this.dataset.fullurl); return false;" title="Abrir imagen">
                                         <img src="${escapeHtml(thumbUrl || fullUrl)}" alt="Imagen" class="message-media-image">
                                     </a>`;
                             } else if (isValidMediaUrl(thumbUrl)) {