diff --git a/History.rdoc b/History.rdoc
index c92b59cec4..90a9dd3915 100644
--- a/History.rdoc
+++ b/History.rdoc
@@ -1,3 +1,8 @@
+=== 4.2.1
+
+* Bug fixes
+  * Fixed infinite loop with CR #339
+
 === 4.2.0 / 2014-12-06
 
 * Major enhancements
diff --git a/lib/rdoc/text.rb b/lib/rdoc/text.rb
index 3a58641ec1..606f15eb0e 100644
--- a/lib/rdoc/text.rb
+++ b/lib/rdoc/text.rb
@@ -68,11 +68,11 @@ def expand_tabs text
     expanded = []
 
     text.each_line do |line|
-      line.gsub!(/^((?:.{8})*?)([^\t\r\n]{0,7})\t/) do
+      nil while line.gsub!(/(?:\G|\r)((?:.{8})*?)([^\t\r\n]{0,7})\t/) do
         r = "#{$1}#{$2}#{' ' * (8 - $2.size)}"
         r.force_encoding text.encoding if Object.const_defined? :Encoding
         r
-      end until line !~ /\t/
+      end
 
       expanded << line
     end
diff --git a/test/test_rdoc_text.rb b/test/test_rdoc_text.rb
index b0c464a659..a69989d15d 100644
--- a/test/test_rdoc_text.rb
+++ b/test/test_rdoc_text.rb
@@ -56,6 +56,9 @@ def test_expand_tabs
 
     assert_equal('.               .',
                  expand_tabs(".\t\t."), 'dot tab tab dot')
+
+    assert_equal('a       a',
+                 Timeout.timeout(1) {expand_tabs("\ra\ta")}, "carriage return")
   end
 
   def test_expand_tabs_encoding