diff --git a/TODO b/TODO
index 55456ea9..d08bdae9 100644
--- a/TODO
+++ b/TODO
@@ -1,4 +1,4 @@
 * Fall back to settings + date of files when no metadata available
-* Filter to generate only the files with .rst extension
+* Add RSS generation
 * Add a licence
 * package it !
diff --git a/pelican/generator.py b/pelican/generator.py
index b44285e0..fa9006f7 100644
--- a/pelican/generator.py
+++ b/pelican/generator.py
@@ -44,7 +44,8 @@ def generate_output(path=None, theme=None, output_path=None, markup=None,
     # get the list of files to parse
     files = []
     for root, dirs, temp_files in os.walk(path, followlinks=True):
-        files.extend([os.sep.join((root, f)) for f in temp_files])
+        files.extend([os.sep.join((root, f)) for f in temp_files 
+                      if f.endswith('.%s' % markup)])
 
     articles, dates, years, tags, categories = [], {}, {}, {}, {}
     # for each file, get the informations.