diff --git a/app/assets/javascripts/app/views/ticket_zoom/article_view.jst.eco b/app/assets/javascripts/app/views/ticket_zoom/article_view.jst.eco
index aaa00e171..ba3dc053d 100644
--- a/app/assets/javascripts/app/views/ticket_zoom/article_view.jst.eco
+++ b/app/assets/javascripts/app/views/ticket_zoom/article_view.jst.eco
@@ -62,13 +62,14 @@
                   <div class="attachment-size"><%- @humanFileSize(attachment.size) %></div>
                 </div>
               <% else: %>
-                <a class="attachment attachment--preview" title="<%- attachment.preferences['Content-Type'] %>" target="_blank" href="<%= App.Config.get('api_path') %>/ticket_attachment/<%= @article.ticket_id %>/<%= @article.id %>/<%= attachment.id %>?disposition=attachment" data-type="attachment"<% if @canDownload(attachment.preferences['Content-Type']): %> download<% end %>>
+                <% content_type = attachment.preferences['Content-Type'] || attachment.preferences['content_type'] %>
+                <a class="attachment attachment--preview" title="<%- content_type %>" target="_blank" href="<%= App.Config.get('api_path') %>/ticket_attachment/<%= @article.ticket_id %>/<%= @article.id %>/<%= attachment.id %>?disposition=attachment" data-type="attachment"<% if @canDownload(content_type): %> download<% end %>>
                   <div class="attachment-icon">
-                  <% if attachment.preferences && attachment.preferences['Content-Type'] && @ContentTypeIcon(attachment.preferences['Content-Type']): %>
-                    <% if @canPreview(attachment.preferences['Content-Type']): %>
+                  <% if attachment.preferences && content_type && @ContentTypeIcon(content_type): %>
+                    <% if @canPreview(content_type): %>
                       <img src="<%= App.Config.get('api_path') %>/ticket_attachment/<%= @article.ticket_id %>/<%= @article.id %>/<%= attachment.id %>?view=preview">
                     <% else: %>
-                      <%- @Icon( @ContentTypeIcon(attachment.preferences['Content-Type']) ) %>
+                      <%- @Icon( @ContentTypeIcon(content_type) ) %>
                     <% end %>
                   <% else: %>
                     <%- @Icon('file-unknown') %>