diff --git a/IPython/core/error.py b/IPython/core/error.py
index 5346498..684cbc8 100644
--- a/IPython/core/error.py
+++ b/IPython/core/error.py
@@ -51,3 +51,10 @@ class StdinNotImplementedError(IPythonCoreError, NotImplementedError):
     For use in IPython kernels, where only some frontends may support
     stdin requests.
     """
+
+class InputRejected(Exception):
+    """Input rejected by ast transformer.
+
+    Raise this in your NodeTransformer to indicate that InteractiveShell should
+    not execute the supplied input.
+    """
diff --git a/IPython/core/interactiveshell.py b/IPython/core/interactiveshell.py
index 0722cdb..56aea6d 100644
--- a/IPython/core/interactiveshell.py
+++ b/IPython/core/interactiveshell.py
@@ -41,7 +41,7 @@ from IPython.core.compilerop import CachingCompiler, check_linecache_ipython
 from IPython.core.display_trap import DisplayTrap
 from IPython.core.displayhook import DisplayHook
 from IPython.core.displaypub import DisplayPublisher
-from IPython.core.error import UsageError
+from IPython.core.error import InputRejected, UsageError
 from IPython.core.extensions import ExtensionManager
 from IPython.core.formatters import DisplayFormatter
 from IPython.core.history import HistoryManager
@@ -54,7 +54,6 @@ from IPython.core.profiledir import ProfileDir
 from IPython.core.prompts import PromptManager
 from IPython.core.usage import default_banner
 from IPython.lib.latextools import LaTeXTool
-from IPython.lib.security import InputRejected
 from IPython.testing.skipdoctest import skip_doctest
 from IPython.utils import PyColorize
 from IPython.utils import io
diff --git a/IPython/core/tests/test_interactiveshell.py b/IPython/core/tests/test_interactiveshell.py
index 326a84b..4d95a68 100644
--- a/IPython/core/tests/test_interactiveshell.py
+++ b/IPython/core/tests/test_interactiveshell.py
@@ -24,8 +24,8 @@ from os.path import join
 
 import nose.tools as nt
 
+from IPython.core.error import InputRejected
 from IPython.core.inputtransformer import InputTransformer
-from IPython.lib.security import InputRejected
 from IPython.testing.decorators import (
     skipif, skip_win32, onlyif_unicode_paths, onlyif_cmds_exist,
 )
diff --git a/IPython/lib/security.py b/IPython/lib/security.py
index 564410d..eab67bb 100644
--- a/IPython/lib/security.py
+++ b/IPython/lib/security.py
@@ -114,13 +114,3 @@ def passwd_check(hashed_passphrase, passphrase):
     h.update(cast_bytes(passphrase, 'utf-8') + cast_bytes(salt, 'ascii'))
 
     return h.hexdigest() == pw_digest
-
-#-----------------------------------------------------------------------------
-# Exception classes
-#-----------------------------------------------------------------------------
-class InputRejected(Exception):
-    """Input rejected by ast transformer.
-
-    To be raised by user-supplied ast.NodeTransformers when an input should not
-    be executed.
-    """