diff --git a/actionpack/lib/action_view/base.rb b/actionpack/lib/action_view/base.rb
index 945246a39a..511858dd9b 100644
--- a/actionpack/lib/action_view/base.rb
+++ b/actionpack/lib/action_view/base.rb
@@ -317,7 +317,8 @@ module ActionView #:nodoc:
           template
         elsif template = self.view_paths[template_file_name]
           template
-        elsif @_render_stack.first && template = self.view_paths["#{template_file_name}.#{@_render_stack.first.format_and_extension}"]
+        elsif (first_render = @_render_stack.first) && first_render.respond_to?(:format_and_extension) &&
+            (template = self.view_paths["#{template_file_name}.#{first_render.format_and_extension}"])
           template
         elsif template_format == :js && template = self.view_paths["#{template_file_name}.html"]
           @template_format = :html
diff --git a/actionpack/test/controller/render_test.rb b/actionpack/test/controller/render_test.rb
index 462fba7045..d5320596d5 100644
--- a/actionpack/test/controller/render_test.rb
+++ b/actionpack/test/controller/render_test.rb
@@ -246,6 +246,15 @@ class TestController < ActionController::Base
            :locals => { :local_name => name }
   end
 
+  def helper_method_to_render_to_string(*args)
+    render_to_string(*args)
+  end
+  helper_method :helper_method_to_render_to_string
+
+  def render_html_only_partial_within_inline
+    render :inline => "Hello world <%= helper_method_to_render_to_string :partial => 'test/partial_with_only_html_version' %>"
+  end
+
   def formatted_html_erb
   end
 
@@ -932,6 +941,11 @@ class RenderTest < ActionController::TestCase
     assert_equal "Goodbye, Local David", @response.body
   end
 
+  def test_rendering_html_only_partial_within_inline_with_js
+    get :render_html_only_partial_within_inline, :format => :js
+    assert_equal "Hello world partial with only html version", @response.body
+  end
+
   def test_should_render_formatted_template
     get :formatted_html_erb
     assert_equal 'formatted html erb', @response.body
diff --git a/actionpack/test/fixtures/test/_partial_with_only_html_version.html.erb b/actionpack/test/fixtures/test/_partial_with_only_html_version.html.erb
new file mode 100644
index 0000000000..00e6b6d6da
--- /dev/null
+++ b/actionpack/test/fixtures/test/_partial_with_only_html_version.html.erb
@@ -0,0 +1 @@
+partial with only html version
\ No newline at end of file