diff --git a/actionpack/lib/action_view/helpers/text_helper.rb b/actionpack/lib/action_view/helpers/text_helper.rb
index 80c80e3143..065f785f74 100644
--- a/actionpack/lib/action_view/helpers/text_helper.rb
+++ b/actionpack/lib/action_view/helpers/text_helper.rb
@@ -77,7 +77,7 @@ module ActionView
       end
 
       begin
-        require_library_or_gem "redcloth"
+        require_library_or_gem "redcloth" unless Object.const_defined?(:RedCloth)
 
         # Returns the text with all the Textile codes turned into HTML-tags.
         # <i>This method is only available if RedCloth can be required</i>.
@@ -104,7 +104,7 @@ module ActionView
       end
 
       begin
-        require_library_or_gem "bluecloth"
+        require_library_or_gem "bluecloth" unless Object.const_defined?(:BlueCloth)
 
         # Returns the text with all the Markdown codes turned into HTML-tags.
         # <i>This method is only available if BlueCloth can be required</i>.