diff --git a/web_responsive/static/src/components/attachment_viewer/attachment_viewer.scss b/web_responsive/static/src/components/attachment_viewer/attachment_viewer.scss
index 6c66cc164..8a6fe5f24 100644
--- a/web_responsive/static/src/components/attachment_viewer/attachment_viewer.scss
+++ b/web_responsive/static/src/components/attachment_viewer/attachment_viewer.scss
@@ -12,7 +12,7 @@
         }
         .o_AttachmentViewer {
             // On-top of navbar
-            z-index: 100;
+            z-index: 1000;
             position: absolute;
             right: 0;
             top: 0;