diff --git a/IPython/irunner.py b/IPython/irunner.py
index e75da7d..6a9d64b 100755
--- a/IPython/irunner.py
+++ b/IPython/irunner.py
@@ -301,7 +301,7 @@ def main():
                    sage=SAGERunner)
 
     try:
-        ext = os.path.splitext(args[0])
+        ext = os.path.splitext(args[0])[-1]
     except IndexError:
         ext = ''
     modes = {'.ipy':'ipython',
diff --git a/doc/ChangeLog b/doc/ChangeLog
index 8d87ca7..7562771 100644
--- a/doc/ChangeLog
+++ b/doc/ChangeLog
@@ -1,3 +1,8 @@
+2007-01-24  Fernando Perez  <Fernando.Perez@colorado.edu>
+
+	* IPython/irunner.py (main): fix small bug where extensions were
+	not being correctly recognized.
+
 2007-01-23  Walter Doerwald  <walter@livinglogic.de>
 
 	* IPython/Extensions/ipipe.py (xiter): Make sure that iterating