diff --git a/lib/xml-sitemap/map.rb b/lib/xml-sitemap/map.rb
index ae5b1ff..328df1b 100644
--- a/lib/xml-sitemap/map.rb
+++ b/lib/xml-sitemap/map.rb
@@ -123,7 +123,7 @@ def render_to(path, options={})
       path = File.expand_path(path)
       path << ".gz" unless path =~ /\.gz\z/i if compress
 
-      if File.exists?(path) && !overwrite
+      if File.exist?(path) && !overwrite
         raise RuntimeError, "File already exists and not overwritable!"
       end