diff --git a/IPython/__init__.py b/IPython/__init__.py
index 03b3116..c224f9a 100644
--- a/IPython/__init__.py
+++ b/IPython/__init__.py
@@ -1,3 +1,4 @@
+# PYTHON_ARGCOMPLETE_OK
 """
 IPython: tools for interactive and parallel computing in Python.
 
diff --git a/IPython/__main__.py b/IPython/__main__.py
index d5123f3..8e9f989 100644
--- a/IPython/__main__.py
+++ b/IPython/__main__.py
@@ -1,3 +1,4 @@
+# PYTHON_ARGCOMPLETE_OK
 # encoding: utf-8
 """Terminal-based IPython entry point.
 """