diff --git a/actionpack/lib/action_view/helpers/text_helper.rb b/actionpack/lib/action_view/helpers/text_helper.rb
index f63d119..d271769 100644
--- a/actionpack/lib/action_view/helpers/text_helper.rb
+++ b/actionpack/lib/action_view/helpers/text_helper.rb
@@ -537,7 +537,7 @@ module ActionView
             href = $&
             punctuation = ''
             # detect already linked URLs
-            if $` =~ /<a\s[^>]*href="$/
+            if $` =~ /<a\s[^>]*href="$|<img\s[^>]*src="$/
               # do not change string; URL is alreay linked
               href
             else
diff --git a/actionpack/test/template/text_helper_test.rb b/actionpack/test/template/text_helper_test.rb
index 816b496..975dfae 100644
--- a/actionpack/test/template/text_helper_test.rb
+++ b/actionpack/test/template/text_helper_test.rb
@@ -359,6 +359,8 @@ class TextHelperTest < ActionView::TestCase
     email_raw = "david@loudthinking.com"
     email_linked = %(<a href="mailto:#{email_raw}">Mail me!</a>)
     assert_equal email_linked, auto_link(email_linked)
+    image = %(<img src="http://www.nu.nl/images/logo_nu_nl.gif" />)
+    assert_equal image, auto_link(image)
   end
 
   def test_auto_link_with_brackets