diff --git a/README.rst b/README.rst
index a19fabe..1e245c1 100644
--- a/README.rst
+++ b/README.rst
@@ -76,10 +76,16 @@ bullets
   level. Defaults to ``'*+-'``.
 
 strong_em_symbol
-  In markdown, both ``*`` and ``_`` are used to encode **strong** or *emphasized* texts. The preferred symbol can be passed through this argument, that defaults to ``*``.
+  In markdown, both ``*`` and ``_`` are used to encode **strong** or
+  *emphasized* texts. Either of these symbols can be chosen by the options
+  ``ASTERISK`` (default) or ``UNDERSCORE`` respectively.
 
 newline_style
-  Defines the style of marking linebreaks (``<br>``) in markdown. The default value ``SPACES`` of this option will adopt the usual two spaces and a newline, while ``BACKSLASH`` will convert a linebreak to ``\\n`` (a backslash an a newline). While the latter convention is non-standard, it is commonly preferred and supported by a lot of interpreters.
+  Defines the style of marking linebreaks (``<br>``) in markdown. The default
+  value ``SPACES`` of this option will adopt the usual two spaces and a newline,
+  while ``BACKSLASH`` will convert a linebreak to ``\\n`` (a backslash an a
+  newline). While the latter convention is non-standard, it is commonly
+  preferred and supported by a lot of interpreters.
 
 Options may be specified as kwargs to the ``markdownify`` function, or as a
 nested ``Options`` class in ``MarkdownConverter`` subclasses.
diff --git a/markdownify/__init__.py b/markdownify/__init__.py
index 08819aa..6f90d73 100644
--- a/markdownify/__init__.py
+++ b/markdownify/__init__.py
@@ -19,6 +19,10 @@ SETEXT = UNDERLINED
 SPACES = 'spaces'
 BACKSLASH = 'backslash'
 
+# Strong and emphasis style
+ASTERISK = '*'
+UNDERSCORE = '_'
+
 
 def escape(text):
     if not text:
@@ -50,7 +54,7 @@ class MarkdownConverter(object):
         autolinks = True
         heading_style = UNDERLINED
         bullets = '*+-'  # An iterable of bullet types.
-        strong_em_symbol = '*'
+        strong_em_symbol = ASTERISK
         newline_style = SPACES
 
     class Options(DefaultOptions):
diff --git a/tests/test_conversions.py b/tests/test_conversions.py
index d07d487..e974c78 100644
--- a/tests/test_conversions.py
+++ b/tests/test_conversions.py
@@ -1,4 +1,4 @@
-from markdownify import markdownify as md, ATX, ATX_CLOSED, BACKSLASH
+from markdownify import markdownify as md, ATX, ATX_CLOSED, BACKSLASH, UNDERSCORE
 import re
 
 
@@ -219,10 +219,10 @@ def test_div():
 
 
 def test_strong_em_symbol():
-    assert md('<strong>Hello</strong>', strong_em_symbol='_') == '__Hello__'
-    assert md('<b>Hello</b>', strong_em_symbol='_') == '__Hello__'
-    assert md('<em>Hello</em>', strong_em_symbol='_') == '_Hello_'
-    assert md('<i>Hello</i>', strong_em_symbol='_') == '_Hello_'
+    assert md('<strong>Hello</strong>', strong_em_symbol=UNDERSCORE) == '__Hello__'
+    assert md('<b>Hello</b>', strong_em_symbol=UNDERSCORE) == '__Hello__'
+    assert md('<em>Hello</em>', strong_em_symbol=UNDERSCORE) == '_Hello_'
+    assert md('<i>Hello</i>', strong_em_symbol=UNDERSCORE) == '_Hello_'
 
 
 def test_newline_style():