diff --git a/IPython/core/profileapp.py b/IPython/core/profileapp.py
index fecdc0d..37f47ee 100644
--- a/IPython/core/profileapp.py
+++ b/IPython/core/profileapp.py
@@ -32,7 +32,7 @@ from IPython.core.profiledir import ProfileDir
 from IPython.utils.importstring import import_item
 from IPython.paths import get_ipython_dir, get_ipython_package_dir
 from IPython.utils import py3compat
-from traitlets import Unicode, Bool, Dict
+from traitlets import Unicode, Bool, Dict, observe
 
 #-----------------------------------------------------------------------------
 # Constants
@@ -149,14 +149,14 @@ class ProfileList(Application):
         )
     ))
 
-    ipython_dir = Unicode(get_ipython_dir(), config=True,
+    ipython_dir = Unicode(get_ipython_dir(),
         help="""
         The name of the IPython directory. This directory is used for logging
         configuration (through profiles), history storage, etc. The default
         is usually $HOME/.ipython. This options can also be specified through
         the environment variable IPYTHONDIR.
         """
-    )
+    ).tag(config=True)
 
 
     def _print_profiles(self, profiles):
@@ -211,15 +211,18 @@ class ProfileCreate(BaseIPythonApplication):
     name = u'ipython-profile'
     description = create_help
     examples = _create_examples
-    auto_create = Bool(True, config=False)
+    auto_create = Bool(True)
     def _log_format_default(self):
         return "[%(name)s] %(message)s"
 
     def _copy_config_files_default(self):
         return True
 
-    parallel = Bool(False, config=True,
-        help="whether to include parallel computing config files")
+    parallel = Bool(False,
+        help="whether to include parallel computing config files"
+    ).tag(config=True)
+
+    @observe('parallel')
     def _parallel_changed(self, name, old, new):
         parallel_files = [   'ipcontroller_config.py',
                             'ipengine_config.py',
diff --git a/IPython/core/prompts.py b/IPython/core/prompts.py
index 70f2e30..0f42557 100644
--- a/IPython/core/prompts.py
+++ b/IPython/core/prompts.py
@@ -285,6 +285,7 @@ class PromptManager(Configurable):
 
     # The number of characters in each prompt which don't contribute to width
     invisible_chars = Dict()
+
     @default('invisible_chars')
     def _invisible_chars_default(self):
         return {'in': 0, 'in2': 0, 'out': 0, 'rewrite':0}
@@ -321,7 +322,9 @@ class PromptManager(Configurable):
         invis_chars = _invisible_characters(self._render(name, color=True))
         self.invisible_chars[name] = invis_chars
 
-    def _update_prompt_trait(self, traitname, new_template):
+    def _update_prompt_trait(self, changes):
+        traitname = changes['name']
+        new_template = changes['new']
         name = traitname[:-9]   # Cut off '_template'
         self.update_prompt(name, new_template)