diff --git a/lib/redcloth.rb b/lib/redcloth.rb
index c4b50487..ae70db74 100644
--- a/lib/redcloth.rb
+++ b/lib/redcloth.rb
@@ -359,16 +359,16 @@ class RedCloth < String
     ]
 
     QTAGS = [
-        ['**', 'b'],
-        ['*', 'strong'],
+        ['**', 'b', :limit],
+        ['*', 'strong', :limit],
         ['??', 'cite', :limit],
         ['-', 'del', :limit],
-        ['__', 'i'],
+        ['__', 'i', :limit],
         ['_', 'em', :limit],
         ['%', 'span', :limit],
         ['+', 'ins', :limit],
-        ['^', 'sup'],
-        ['~', 'sub']
+        ['^', 'sup', :limit],
+        ['~', 'sub', :limit]
     ] 
     QTAGS.collect! do |rc, ht, rtype|
         rcq = Regexp::quote rc
diff --git a/test/unit/helpers/application_helper_test.rb b/test/unit/helpers/application_helper_test.rb
index 1da25b6f..0048ce5b 100644
--- a/test/unit/helpers/application_helper_test.rb
+++ b/test/unit/helpers/application_helper_test.rb
@@ -29,6 +29,7 @@ class ApplicationHelperTest < HelperTestCase
   def test_auto_links
     to_test = {
       'http://foo.bar' => '<a class="external" href="http://foo.bar">http://foo.bar</a>',
+      'http://foo.bar/~user' => '<a class="external" href="http://foo.bar/~user">http://foo.bar/~user</a>',
       'http://foo.bar.' => '<a class="external" href="http://foo.bar">http://foo.bar</a>.',
       'http://foo.bar/foo.bar#foo.bar.' => '<a class="external" href="http://foo.bar/foo.bar#foo.bar">http://foo.bar/foo.bar#foo.bar</a>.',
       'www.foo.bar' => '<a class="external" href="http://www.foo.bar">www.foo.bar</a>',