diff --git a/lib/rdoc/generator/pot/po.rb b/lib/rdoc/generator/pot/po.rb
index 447cb60ead..401025f6e8 100644
--- a/lib/rdoc/generator/pot/po.rb
+++ b/lib/rdoc/generator/pot/po.rb
@@ -27,12 +27,7 @@ def add(entry)
   # Returns PO format text for the PO.
 
   def to_s
-    po = ''
-    sort_entries.each do |entry|
-      po += "\n" unless po.empty?
-      po += entry.to_s
-    end
-    po
+    sort_entries.map(&:to_s).join("\n")
   end
 
   private