diff --git a/actionpack/CHANGELOG b/actionpack/CHANGELOG
index 7f9a948f66..40cba442d4 100644
--- a/actionpack/CHANGELOG
+++ b/actionpack/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* Handle corner case with image_tag when passed 'messed up' image names. #9018 [duncanbeevers, mpalmer]
+
 * Add label_tag helper for generating elements. #10802 [DefV]
 
 * Introduce TemplateFinder to handle view paths and lookups.  #10800 [Pratik Naik] 
diff --git a/actionpack/lib/action_view/helpers/asset_tag_helper.rb b/actionpack/lib/action_view/helpers/asset_tag_helper.rb
index 30f136103d..12fbbb0dd6 100644
--- a/actionpack/lib/action_view/helpers/asset_tag_helper.rb
+++ b/actionpack/lib/action_view/helpers/asset_tag_helper.rb
@@ -398,7 +398,7 @@ module ActionView
         options.symbolize_keys!
 
         options[:src] = path_to_image(source)
-        options[:alt] ||= File.basename(options[:src], '.*').split('.').first.capitalize
+        options[:alt] ||= File.basename(options[:src], '.*').split('.').first.to_s.capitalize
 
         if size = options.delete(:size)
           options[:width], options[:height] = size.split("x") if size =~ %r{^\d+x\d+$}
diff --git a/actionpack/test/template/asset_tag_helper_test.rb b/actionpack/test/template/asset_tag_helper_test.rb
index 37392b9f67..3b614ad2a0 100644
--- a/actionpack/test/template/asset_tag_helper_test.rb
+++ b/actionpack/test/template/asset_tag_helper_test.rb
@@ -131,6 +131,7 @@ class AssetTagHelperTest < Test::Unit::TestCase
 
   ImageLinkToTag = {
     %(image_tag("xml.png")) => %(<img alt="Xml" src="/images/xml.png" />),
+    %(image_tag("..jpg")) => %(<img alt="" src="/images/..jpg" />),
     %(image_tag("rss.gif", :alt => "rss syndication")) => %(<img alt="rss syndication" src="/images/rss.gif" />),
     %(image_tag("gold.png", :size => "45x70")) => %(<img alt="Gold" height="70" src="/images/gold.png" width="45" />),
     %(image_tag("gold.png", "size" => "45x70")) => %(<img alt="Gold" height="70" src="/images/gold.png" width="45" />),