diff --git a/nose/config.py b/nose/config.py

index 125eb55..ad01e61 100644

--- a/nose/config.py

+++ b/nose/config.py

@@ -139,7 +139,7 @@ class ConfiguredDefaultsOptionParser(object):

 class Config(object):

-    """nose configuration.

+    r"""nose configuration.

     Instances of Config are used throughout nose to configure

     behavior, including plugin lists. Here are the default values for

diff --git a/nose/ext/dtcompat.py b/nose/ext/dtcompat.py

index 332cf08..b5698c5 100644

--- a/nose/ext/dtcompat.py

+++ b/nose/ext/dtcompat.py

@@ -683,7 +683,7 @@ class DocTestParser:

     # This regular expression finds the indentation of every non-blank

     # line in a string.

-    _INDENT_RE = re.compile('^([ ]*)(?=\S)', re.MULTILINE)

+    _INDENT_RE = re.compile(r'^([ ]*)(?=\S)', re.MULTILINE)

     def _min_indent(self, s):

         "Return the minimum indentation of any non-blank line in `s`"

@@ -1018,7 +1018,7 @@ class DocTestFinder:

         if lineno is not None:

             if source_lines is None:

                 return lineno+1

-            pat = re.compile('(^|.*:)\s*\w*("|\')')

+            pat = re.compile(r'(^|.*:)\s*\w*("|\')')

             for lineno in range(lineno, len(source_lines)):

                 if pat.match(source_lines[lineno]):

                     return lineno

@@ -1427,11 +1427,11 @@ class OutputChecker:

         # blank line, unless the DONT_ACCEPT_BLANKLINE flag is used.

         if not (optionflags & DONT_ACCEPT_BLANKLINE):

             # Replace <BLANKLINE> in want with a blank line.

-            want = re.sub('(?m)^%s\s*?$' % re.escape(BLANKLINE_MARKER),

+            want = re.sub(r'(?m)^%s\s*?$' % re.escape(BLANKLINE_MARKER),

                           '', want)

             # If a line in got contains only spaces, then remove the

             # spaces.

-            got = re.sub('(?m)^\s*?$', '', got)

+            got = re.sub(r'(?m)^\s*?$', '', got)

             if got == want:

                 return True

diff --git a/nose/inspector.py b/nose/inspector.py

index a6c4a3e..ad22c0c 100644

--- a/nose/inspector.py

+++ b/nose/inspector.py

@@ -107,7 +107,7 @@ def tbsource(tb, context=6):

 def find_inspectable_lines(lines, pos):

-    """Find lines in home that are inspectable.

+    r"""Find lines in home that are inspectable.

     Walk back from the err line up to 3 lines, but don't walk back over

     changes in indent level.