diff --git a/pre_commit/languages/node.py b/pre_commit/languages/node.py
index 9f15f43f..bc4fa007 100644
--- a/pre_commit/languages/node.py
+++ b/pre_commit/languages/node.py
@@ -1,17 +1,25 @@
 import contextlib
 from plumbum import local
-from plumbum.machines.session import ShellSession
-from pre_commit.languages import helpers
 
+from pre_commit.languages import helpers
 from pre_commit.languages import python
 
+
 NODE_ENV = 'node_env'
 
+
+class NodeEnv(object):
+    def __init__(self, py_env):
+        self.py_env = py_env
+        self.env_prefix = '. {0}/bin/activate &&'.format(NODE_ENV)
+
+    def run(self, cmd, **kwargs):
+        return self.py_env.run(' '.join([self.env_prefix, cmd]), **kwargs)
+
+
 @contextlib.contextmanager
-def in_env():
-    with ShellSession(local['bash'].popen()) as env:
-        env.run('. {0}/bin/activate'.format(NODE_ENV))
-        yield env
+def in_env(py_env):
+    yield NodeEnv(py_env)
 
 
 def install_environment():
@@ -20,21 +28,17 @@ def install_environment():
     if local.path('node_env').exists():
         return
 
-    # Install a virtualenv
     local['virtualenv'][python.PY_ENV]()
 
     with python.in_env() as python_env:
         python_env.run('pip install nodeenv')
+        python_env.run('nodeenv {0}'.format(NODE_ENV))
 
-        print "Creating nodeenv"
-        local['nodeenv'][NODE_ENV]()
-        print "Done nodeenv"
-
-        with in_env() as node_env:
+        with in_env(python_env) as node_env:
             node_env.run('npm install -g')
 
 
 def run_hook(hook, file_args):
-    with python.in_env():
-        with in_env() as node_env:
+    with python.in_env() as py_env:
+        with in_env(py_env) as node_env:
             return helpers.run_hook(node_env, hook, file_args)
\ No newline at end of file
diff --git a/pre_commit/languages/python.py b/pre_commit/languages/python.py
index 9626f108..850ad660 100644
--- a/pre_commit/languages/python.py
+++ b/pre_commit/languages/python.py
@@ -1,34 +1,37 @@
 
 import contextlib
 from plumbum import local
-from plumbum.machines.session import ShellSession
 from pre_commit.languages import helpers
 
 PY_ENV = 'py_env'
 
 
+class PythonEnv(object):
+    def __init__(self):
+        self.env_prefix = '. {0}/bin/activate &&'.format(PY_ENV)
+
+    def run(self, cmd, **kwargs):
+        return local['bash']['-c', ' '.join([self.env_prefix, cmd])].run(**kwargs)
+
+
 @contextlib.contextmanager
 def in_env():
-    with ShellSession(local['bash'].popen()) as env:
-        env.run('source {0}/bin/activate'.format(PY_ENV))
-        yield env
+    yield PythonEnv()
 
 
 def install_environment():
     assert local.path('setup.py').exists()
     # Return immediately if we already have a virtualenv
-    if local.path('py_env').exists():
+    if local.path(PY_ENV).exists():
         return
 
     # Install a virtualenv
     local['virtualenv'][PY_ENV]()
-
     with in_env() as env:
-        # Run their setup.py
         env.run('pip install .')
 
 
 def run_hook(hook, file_args):
+    # TODO: batch filenames
     with in_env() as env:
-        # TODO: batch filenames
-        return helpers.run_hook(env, hook, file_args)
\ No newline at end of file
+        return helpers.run_hook(env, hook, file_args)