diff --git a/IPython/core/application.py b/IPython/core/application.py
index d6ad998..b8f0472 100644
--- a/IPython/core/application.py
+++ b/IPython/core/application.py
@@ -260,14 +260,10 @@ class BaseIPythonApplication(Application):
         old = change['old']
         new = change['new']
         if old is not Undefined:
-            str_old = py3compat.cast_bytes_py2(os.path.abspath(old),
-                sys.getfilesystemencoding()
-            )
+            str_old = os.path.abspath(old)
             if str_old in sys.path:
                 sys.path.remove(str_old)
-        str_path = py3compat.cast_bytes_py2(os.path.abspath(new),
-            sys.getfilesystemencoding()
-        )
+        str_path = os.path.abspath(new)
         sys.path.append(str_path)
         ensure_dir_exists(new)
         readme = os.path.join(new, 'README')
diff --git a/IPython/core/display.py b/IPython/core/display.py
index 8fd52b5..e1875e1 100644
--- a/IPython/core/display.py
+++ b/IPython/core/display.py
@@ -18,7 +18,7 @@ import struct
 import sys
 import warnings
 
-from IPython.utils.py3compat import cast_bytes_py2, cast_unicode
+from IPython.utils.py3compat import cast_unicode
 from IPython.testing.skipdoctest import skip_doctest
 
 __all__ = ['display', 'display_pretty', 'display_html', 'display_markdown',
@@ -596,7 +596,6 @@ class SVG(DisplayObject):
             return
         # parse into dom object
         from xml.dom import minidom
-        svg = cast_bytes_py2(svg)
         x = minidom.parseString(svg)
         # get svg tag (should be 1)
         found_svg = x.getElementsByTagName('svg')
diff --git a/IPython/core/interactiveshell.py b/IPython/core/interactiveshell.py
index e93ff0b..a94e9a5 100644
--- a/IPython/core/interactiveshell.py
+++ b/IPython/core/interactiveshell.py
@@ -887,7 +887,7 @@ class InteractiveShell(SingletonConfigurable):
             main_mod = self._main_mod_cache[filename]
         except KeyError:
             main_mod = self._main_mod_cache[filename] = types.ModuleType(
-                        py3compat.cast_bytes_py2(modname),
+                        modname,
                         doc="Module created for script run in IPython")
         else:
             main_mod.__dict__.clear()
@@ -1875,7 +1875,7 @@ class InteractiveShell(SingletonConfigurable):
             In [1]: _ip.set_next_input("Hello Word")
             In [2]: Hello Word_  # cursor is here
         """
-        self.rl_next_input = py3compat.cast_bytes_py2(s)
+        self.rl_next_input = s
 
     def _indent_current_str(self):
         """return the current level of indentation as a string"""
diff --git a/IPython/core/magics/osm.py b/IPython/core/magics/osm.py
index 72f264e..9436ee4 100644
--- a/IPython/core/magics/osm.py
+++ b/IPython/core/magics/osm.py
@@ -428,7 +428,7 @@ class OSMagics(Magics):
             err = "refusing to set env var with whitespace: '{0}'"
             err = err.format(val)
             raise UsageError(err)
-        os.environ[py3compat.cast_bytes_py2(var)] = py3compat.cast_bytes_py2(val)
+        os.environ[var] = val
         print('env: {0}={1}'.format(var,val))
 
     @line_magic
diff --git a/IPython/core/page.py b/IPython/core/page.py
index 0a9e4f0..4499609 100644
--- a/IPython/core/page.py
+++ b/IPython/core/page.py
@@ -231,8 +231,7 @@ def pager_page(strng, start=0, screen_lines=0, pager_cmd=None):
                 pager = os.popen(pager_cmd, 'w')
                 try:
                     pager_encoding = pager.encoding or sys.stdout.encoding
-                    pager.write(py3compat.cast_bytes_py2(
-                        strng, encoding=pager_encoding))
+                    pager.write(strng)
                 finally:
                     retval = pager.close()
             except IOError as msg:  # broken pipe when user quits
diff --git a/IPython/utils/syspathcontext.py b/IPython/utils/syspathcontext.py
index 8961203..bd1c515 100644
--- a/IPython/utils/syspathcontext.py
+++ b/IPython/utils/syspathcontext.py
@@ -14,23 +14,14 @@ Authors:
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
-#-----------------------------------------------------------------------------
-# Imports
-#-----------------------------------------------------------------------------
-
 import sys
 
-from IPython.utils.py3compat import cast_bytes_py2
-
-#-----------------------------------------------------------------------------
-# Code
-#-----------------------------------------------------------------------------
 
 class appended_to_syspath(object):
     """A context for appending a directory to sys.path for a second."""
 
     def __init__(self, dir):
-        self.dir = cast_bytes_py2(dir, sys.getdefaultencoding())
+        self.dir = dir
 
     def __enter__(self):
         if self.dir not in sys.path:
@@ -52,7 +43,7 @@ class prepended_to_syspath(object):
     """A context for prepending a directory to sys.path for a second."""
 
     def __init__(self, dir):
-        self.dir = cast_bytes_py2(dir, sys.getdefaultencoding())
+        self.dir = dir
 
     def __enter__(self):
         if self.dir not in sys.path: