diff --git a/IPython/frontend/html/notebook/kernelmanager.py b/IPython/frontend/html/notebook/kernelmanager.py
index c79ab6f..70d2f4f 100644
--- a/IPython/frontend/html/notebook/kernelmanager.py
+++ b/IPython/frontend/html/notebook/kernelmanager.py
@@ -79,6 +79,11 @@ class MultiKernelManager(LoggingConfigurable):
 
         The caller can pick a kernel_id by passing one in as a keyword arg,
         otherwise one will be picked using a uuid.
+
+        To silence the kernel's stdout/stderr, call this using::
+
+            km.start_kernel(stdout=PIPE, stderr=PIPE)
+
         """
         kernel_id = kwargs.pop('kernel_id', unicode(uuid.uuid4()))
         if kernel_id in self:
diff --git a/IPython/frontend/html/notebook/tests/test_kernelmanager.py b/IPython/frontend/html/notebook/tests/test_kernelmanager.py
index 870f1a9..3b8c18a 100644
--- a/IPython/frontend/html/notebook/tests/test_kernelmanager.py
+++ b/IPython/frontend/html/notebook/tests/test_kernelmanager.py
@@ -1,5 +1,6 @@
 """Tests for the notebook kernel and session manager."""
 
+from subprocess import PIPE
 import time
 from unittest import TestCase
 
@@ -20,7 +21,7 @@ class TestKernelManager(TestCase):
         return km
 
     def _run_lifecycle(self, km):
-        kid = km.start_kernel()
+        kid = km.start_kernel(stdout=PIPE, stderr=PIPE)
         self.assertTrue(kid in km)
         self.assertTrue(kid in km.list_kernel_ids())
         self.assertEqual(len(km),1)
@@ -40,7 +41,7 @@ class TestKernelManager(TestCase):
         self.assertTrue(not kid in km)
 
     def _run_cinfo(self, km, transport, ip):
-        kid = km.start_kernel()
+        kid = km.start_kernel(stdout=PIPE, stderr=PIPE)
         k = km.get_kernel(kid)
         cinfo = km.get_connection_info(kid)
         self.assertEqual(transport, cinfo['transport'])
diff --git a/IPython/zmq/tests/test_kernelmanager.py b/IPython/zmq/tests/test_kernelmanager.py
index 05313a6..f6482c2 100644
--- a/IPython/zmq/tests/test_kernelmanager.py
+++ b/IPython/zmq/tests/test_kernelmanager.py
@@ -1,5 +1,6 @@
 """Tests for the notebook kernel and session manager."""
 
+from subprocess import PIPE
 import time
 from unittest import TestCase
 
@@ -19,7 +20,7 @@ class TestKernelManager(TestCase):
         return km
 
     def _run_lifecycle(self, km):
-        km.start_kernel()
+        km.start_kernel(stdout=PIPE, stderr=PIPE)
         km.start_channels(shell=True, iopub=False, stdin=False, hb=False)
         km.restart_kernel()
         # We need a delay here to give the restarting kernel a chance to
@@ -28,7 +29,7 @@ class TestKernelManager(TestCase):
         # message for the restart sometimes hasn't been sent to the kernel.
         # Because linger is oo on the shell channel, the context can't
         # close until the message is sent to the kernel, which is not dead.
-        time.sleep()
+        time.sleep(1.0)
         km.interrupt_kernel()
         self.assertTrue(isinstance(km, KernelManager))
         km.shutdown_kernel()