diff --git a/nbconvert.py b/nbconvert.py
index bcdd559..cdcd3ae 100755
--- a/nbconvert.py
+++ b/nbconvert.py
@@ -12,7 +12,6 @@ called nb_figure_NN.png.
 #-----------------------------------------------------------------------------
 from __future__ import print_function
 
-
 # From IPython
 from IPython.external import argparse
 
@@ -25,35 +24,40 @@ from converters.latex import ConverterLaTeX
 from converters.notebook import ConverterNotebook
 from converters.python import ConverterPy
 
-known_formats = "rst (default), html, blogger-html, latex, markdown, py"
+
+# When adding a new format, make sure to add it to the `converters`
+# dictionary below. This is used to create the list of known formats,
+# which gets printed in case an unknown format is encounteres, as well
+# as in the help
+
+converters = {
+    'rst': ConverterRST,
+    'markdown': ConverterMarkdown,
+    'html': ConverterHTML,
+    'blogger-html': ConverterBloggerHTML,
+    'latex': ConverterLaTeX,
+    'py': ConverterPy,
+    }
+
+default_format = 'rst'
+
+# Extract the list of known formats and mark the first format as the default.
+known_formats = ', '.join([key + " (default)" if key == default_format else key
+                           for key in converters])
+
 
 def main(infile, format='rst'):
     """Convert a notebook to html in one step"""
-    # XXX: this is just quick and dirty for now. When adding a new format,
-    # make sure to add it to the `known_formats` string above, which gets
-    # printed in in the catch-all else, as well as in the help
-    if format == 'rst':
-        converter = ConverterRST(infile)
-        converter.render()
-    elif format == 'markdown':
-        converter = ConverterMarkdown(infile)
-        converter.render()
-    elif format == 'html':
-        converter = ConverterHTML(infile)
-        converter.render()
-    elif format == 'blogger-html':
-        converter = ConverterBloggerHTML(infile)
-        converter.render()
-    elif format == 'latex':
-        converter = ConverterLaTeX(infile)
-        converter.render()
-    elif format == 'py':
-        converter = ConverterPy(infile)
-        converter.render()
-    else:
+
+    try:
+        ConverterClass = converters[format]
+    except KeyError:
         raise SystemExit("Unknown format '%s', " % format +
                 "known formats are: " + known_formats)
 
+    converter = ConverterClass(infile)
+    converter.render()
+
 #-----------------------------------------------------------------------------
 # Script main
 #-----------------------------------------------------------------------------
diff --git a/tests/test_simple.py b/tests/test_simple.py
index 69f96d8..e5befc2 100644
--- a/tests/test_simple.py
+++ b/tests/test_simple.py
@@ -21,7 +21,7 @@ def clean_dir():
 def test_simple():
     c = ConverterRST(fname)
     f = c.render()
-    nt.assert_true('rst' in f, 'changed file extension to rst')
+    nt.assert_true(f.endswith('.rst'), 'changed file extension to rst')
 
 
 @nt.with_setup(clean_dir, clean_dir)