diff --git a/addons/mail/static/src/components/attachment/attachment.xml b/addons/mail/static/src/components/attachment/attachment.xml
index 27930259bdf..93b8e1620f7 100644
--- a/addons/mail/static/src/components/attachment/attachment.xml
+++ b/addons/mail/static/src/components/attachment/attachment.xml
@@ -6,7 +6,7 @@
             t-att-class="{
                 'o-downloadable': props.isDownloadable,
                 'o-editable': props.isEditable,
-                'o-has-card-details': detailsMode === 'card',
+                'o-has-card-details': attachment and detailsMode === 'card',
                 'o-isUploading': attachment and attachment.isUploading,
                 'o-viewable': attachment and attachment.isViewable,
             }" t-att-title="attachment ? attachment.displayName : undefined" t-att-data-attachment-local-id="attachment ? attachment.localId : undefined"