diff --git a/lib/oneboxer/image_onebox.rb b/lib/oneboxer/image_onebox.rb
index d49725043..bc2248335 100644
--- a/lib/oneboxer/image_onebox.rb
+++ b/lib/oneboxer/image_onebox.rb
@@ -3,7 +3,7 @@ require_dependency 'oneboxer/base_onebox'
 module Oneboxer
   class ImageOnebox < BaseOnebox
 
-    matcher /^https?:\/\/.*\.(jpg|png|gif|jpeg)$/
+    matcher /^(https?:)?\/\/.+\.(png|jpg|jpeg|gif|bmp|tif|tiff)$/i
 
     def onebox
       Oneboxer::BaseOnebox.image_html(@url, nil, @url)
diff --git a/lib/pretty_text.rb b/lib/pretty_text.rb
index c1619d8f9..7cfe7c93a 100644
--- a/lib/pretty_text.rb
+++ b/lib/pretty_text.rb
@@ -163,7 +163,7 @@ module PrettyText
   def self.apply_cdn(html, url)
     return html unless url
 
-    image = /\.(jpg|jpeg|gif|png|tiff|tif|bmp)$/
+    image = /\.(png|jpg|jpeg|gif|bmp|tif|tiff)$/i
     relative = /^\/[^\/]/
 
     doc = Nokogiri::HTML.fragment(html)