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 57f537454390..7be9050c6aed 100644
--- a/web_responsive/static/src/components/attachment_viewer/attachment_viewer.scss
+++ b/web_responsive/static/src/components/attachment_viewer/attachment_viewer.scss
@@ -14,7 +14,7 @@
         }
         .o_AttachmentViewer {
             // On-top of navbar
-            z-index: 10;
+            z-index: 1100;
             position: absolute;
             right: 0;
             top: 0;