diff --git a/IPython/nbformat.py b/IPython/nbformat.py
deleted file mode 100644
index 310277d..0000000
--- a/IPython/nbformat.py
+++ /dev/null
@@ -1,19 +0,0 @@
-"""
-Shim to maintain backwards compatibility with old IPython.nbformat imports.
-"""
-# Copyright (c) IPython Development Team.
-# Distributed under the terms of the Modified BSD License.
-
-import sys
-from warnings import warn
-
-from IPython.utils.shimmodule import ShimModule, ShimWarning
-
-warn("The `IPython.nbformat` package has been deprecated since IPython 4.0. "
-     "You should import from nbformat instead.", ShimWarning)
-
-# Unconditionally insert the shim into sys.modules so that further import calls
-# trigger the custom attribute access above
-
-sys.modules['IPython.nbformat'] = ShimModule(
-    src='IPython.nbformat', mirror='nbformat')