diff --git a/app/helpers/gantt_helper.rb b/app/helpers/gantt_helper.rb
index 03bd8451f..477410f09 100644
--- a/app/helpers/gantt_helper.rb
+++ b/app/helpers/gantt_helper.rb
@@ -25,7 +25,7 @@ module GanttHelper
           params.merge(gantt.params.merge(:zoom => (gantt.zoom+1))),
           :class => 'icon icon-zoom-in'
       else
-        content_tag('span', l(:text_zoom_in), :class => 'icon icon-zoom-in')
+        content_tag('span', l(:text_zoom_in), :class => 'icon icon-zoom-in').html_safe
       end
 
     when :out
@@ -34,7 +34,7 @@ module GanttHelper
           params.merge(gantt.params.merge(:zoom => (gantt.zoom-1))),
           :class => 'icon icon-zoom-out'
       else
-        content_tag('span', l(:text_zoom_out), :class => 'icon icon-zoom-out')
+        content_tag('span', l(:text_zoom_out), :class => 'icon icon-zoom-out').html_safe
       end
     end
   end