diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index e9cbf6dd4..6b5dd08e0 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -589,7 +589,7 @@ module ApplicationHelper
     end
     return '' if text.blank?
     project = options[:project] || @project || (obj && obj.respond_to?(:project) ? obj.project : nil)
-    only_path = options.delete(:only_path) == false ? false : true
+    @only_path = only_path = options.delete(:only_path) == false ? false : true
 
     text = text.dup
     macros = catch_macros(text)
diff --git a/lib/redmine/wiki_formatting/macros.rb b/lib/redmine/wiki_formatting/macros.rb
index d3a728963..df4f7a15f 100644
--- a/lib/redmine/wiki_formatting/macros.rb
+++ b/lib/redmine/wiki_formatting/macros.rb
@@ -236,8 +236,8 @@ module Redmine
         size = nil unless size > 0
         if obj && obj.respond_to?(:attachments) && attachment = Attachment.latest_attach(obj.attachments, filename)
           title = options[:title] || attachment.title
-          thumbnail_url = url_for(:controller => 'attachments', :action => 'thumbnail', :id => attachment, :size => size, :only_path => false)
-          image_url = url_for(:controller => 'attachments', :action => 'show', :id => attachment, :only_path => false)
+          thumbnail_url = url_for(:controller => 'attachments', :action => 'thumbnail', :id => attachment, :size => size, :only_path => @only_path)
+          image_url = url_for(:controller => 'attachments', :action => 'show', :id => attachment, :only_path => @only_path)
 
           img = image_tag(thumbnail_url, :alt => attachment.filename)
           link_to(img, image_url, :class => 'thumbnail', :title => title)
diff --git a/test/unit/lib/redmine/wiki_formatting/macros_test.rb b/test/unit/lib/redmine/wiki_formatting/macros_test.rb
index 443b6f4d8..7f5308d1b 100644
--- a/test/unit/lib/redmine/wiki_formatting/macros_test.rb
+++ b/test/unit/lib/redmine/wiki_formatting/macros_test.rb
@@ -302,26 +302,35 @@ RAW
   end
 
   def test_macro_thumbnail
-    link = link_to('<img alt="testfile.PNG" src="http://test.host/attachments/thumbnail/17" />'.html_safe,
-                   "http://test.host/attachments/17",
+    link = link_to('<img alt="testfile.PNG" src="/attachments/thumbnail/17" />'.html_safe,
+                   "/attachments/17",
                    :class => "thumbnail",
                    :title => "testfile.PNG")
     assert_equal "<p>#{link}</p>",
                  textilizable("{{thumbnail(testfile.png)}}", :object => Issue.find(14))
   end
 
-  def test_macro_thumbnail_with_size
-    link = link_to('<img alt="testfile.PNG" src="http://test.host/attachments/thumbnail/17/200" />'.html_safe,
+  def test_macro_thumbnail_with_full_path
+    link = link_to('<img alt="testfile.PNG" src="http://test.host/attachments/thumbnail/17" />'.html_safe,
                    "http://test.host/attachments/17",
                    :class => "thumbnail",
                    :title => "testfile.PNG")
+    assert_equal "<p>#{link}</p>",
+                 textilizable("{{thumbnail(testfile.png)}}", :object => Issue.find(14), :only_path => false)
+  end
+
+  def test_macro_thumbnail_with_size
+    link = link_to('<img alt="testfile.PNG" src="/attachments/thumbnail/17/200" />'.html_safe,
+                   "/attachments/17",
+                   :class => "thumbnail",
+                   :title => "testfile.PNG")
     assert_equal "<p>#{link}</p>",
                  textilizable("{{thumbnail(testfile.png, size=200)}}", :object => Issue.find(14))
   end
 
   def test_macro_thumbnail_with_title
-    link = link_to('<img alt="testfile.PNG" src="http://test.host/attachments/thumbnail/17" />'.html_safe,
-                   "http://test.host/attachments/17",
+    link = link_to('<img alt="testfile.PNG" src="/attachments/thumbnail/17" />'.html_safe,
+                   "/attachments/17",
                    :class => "thumbnail",
                    :title => "Cool image")
     assert_equal "<p>#{link}</p>",