diff --git a/addons/web_editor/models/ir_attachment.py b/addons/web_editor/models/ir_attachment.py
index 36c44320c48..7a7d9f83111 100644
--- a/addons/web_editor/models/ir_attachment.py
+++ b/addons/web_editor/models/ir_attachment.py
@@ -26,13 +26,23 @@ class IrAttachment(models.Model):
     @api.depends('mimetype', 'url', 'name')
     def _compute_image_src(self):
         for attachment in self:
+            # Only add a src for supported images
             if attachment.mimetype not in ['image/gif', 'image/jpe', 'image/jpeg', 'image/jpg', 'image/gif', 'image/png', 'image/svg+xml']:
                 attachment.image_src = False
+                continue
+
+            if attachment.type == 'url':
+                attachment.image_src = attachment.url
             else:
-                attachment.image_src = attachment.url or '/web/image/%s/%s' % (
-                    attachment.id,
-                    url_quote(attachment.name or ''),
-                )
+                # Adding unique in URLs for cache-control
+                unique = attachment.checksum[:8]
+                if attachment.url:
+                    # For attachments-by-url, unique is used as a cachebuster. They
+                    # currently do not leverage max-age headers.
+                    attachment.image_src = '%s?unique=%s' % (attachment.url, unique)
+                else:
+                    name = url_quote(attachment.name)
+                    attachment.image_src = '/web/image/%s-%s/%s' % (attachment.id, unique, name)
 
     @api.depends('datas')
     def _compute_image_size(self):
diff --git a/addons/web_editor/static/src/js/wysiwyg/widgets/media.js b/addons/web_editor/static/src/js/wysiwyg/widgets/media.js
index 87fac3cd640..3ccc9016a02 100644
--- a/addons/web_editor/static/src/js/wysiwyg/widgets/media.js
+++ b/addons/web_editor/static/src/js/wysiwyg/widgets/media.js
@@ -379,7 +379,12 @@ var FileWidget = SearchableMediaWidget.extend({
             }).open();
             optimizeDialog.on('attachment_updated', self, function (ev) {
                 optimizeDialog.off('closed');
-                resolve(ev.data);
+                if (self.$media[0].getAttribute('src') === attachment.image_src) {
+                    self.$media[0].src = ev.data.image_src;
+                }
+                Object.assign(attachment, ev.data);
+                $attachmentCell.find('img')[0].src = attachment.image_src;
+                resolve(attachment);
             });
             optimizeDialog.on('closed', self, function () {
                 self.noSave = true;