diff --git a/sphinx_intl/basic.py b/sphinx_intl/basic.py
index 6d30c99..fa035e3 100644
--- a/sphinx_intl/basic.py
+++ b/sphinx_intl/basic.py
@@ -22,14 +22,15 @@ def get_lang_dirs(path):
 # ==================================
 # commands
 
-def update(locale_dir, pot_dir, languages, line_width=76):
+def update(locale_dir, pot_dir, languages, line_width=76, ignore_obsolete=False):
     """
     Update specified language's po files from pot.
 
     :param unicode locale_dir: path for locale directory
     :param unicode pot_dir: path for pot directory
     :param tuple languages: languages to update po files
-    :param number line_width: maximum line wdith of po files
+    :param number line_width: maximum line width of po files
+    :param bool ignore_obsolete: ignore obsolete entries in po files
     :return: {'create': 0, 'update': 0, 'notchanged': 0}
     :rtype: dict
     """
@@ -61,7 +62,8 @@ def update(locale_dir, pot_dir, languages, line_width=76):
                         status['update'] += 1
                         click.echo('Update: {0} +{1}, -{2}'.format(
                             po_file, len(added), len(deleted)))
-                        c.dump_po(po_file, cat, line_width)
+                        c.dump_po(po_file, cat, width=line_width,
+                                  ignore_obsolete=ignore_obsolete)
                     else:
                         status['notchanged'] += 1
                         click.echo('Not Changed: {0}'.format(po_file))
@@ -69,7 +71,8 @@ def update(locale_dir, pot_dir, languages, line_width=76):
                     status['create'] += 1
                     click.echo('Create: {0}'.format(po_file))
                     cat_pot.locale = lang
-                    c.dump_po(po_file, cat_pot, line_width)
+                    c.dump_po(po_file, cat_pot, width=line_width,
+                              ignore_obsolete=ignore_obsolete)
 
     return status
 
diff --git a/sphinx_intl/catalog.py b/sphinx_intl/catalog.py
index 714416c..f8642a3 100644
--- a/sphinx_intl/catalog.py
+++ b/sphinx_intl/catalog.py
@@ -6,10 +6,11 @@
 from babel.messages import pofile, mofile
 
 
-def load_po(filename):
+def load_po(filename, **kwargs):
     """read po/pot file and return catalog object
 
     :param unicode filename: path to po/pot file
+    :param kwargs: keyword arguments to forward to babel's read_po call
     :return: catalog object
     """
     # pre-read to get charset
@@ -20,27 +21,36 @@ def load_po(filename):
     # To decode lines by babel, read po file as binary mode and specify charset for
     # read_po function.
     with io.open(filename, 'rb') as f:  # FIXME: encoding VS charset
-        return pofile.read_po(f, charset=charset)
+        return pofile.read_po(f, charset=charset, **kwargs)
 
 
-def dump_po(filename, catalog, line_width=76):
+def dump_po(filename, catalog, **kwargs):
     """write po/pot file from catalog object
 
     :param unicode filename: path to po file
     :param catalog: catalog object
-    :param line_width: maximum line wdith of po files
+    :param kwargs: keyword arguments to forward to babel's write_po call; also
+                    accepts a deprecated `line_width` option to forward to
+                    write_po's `width` option
     :return: None
     """
     dirname = os.path.dirname(filename)
     if not os.path.exists(dirname):
         os.makedirs(dirname)
 
+    # (compatibility) line_width was the original argument used to forward
+    # line width hints into write_po's `width` argument; if provided,
+    # set/override the width value
+    if 'line_width' in kwargs:
+        kwargs['width'] = kwargs['line_width']
+        del kwargs['line_width']
+
     # Because babel automatically encode strings, file should be open as binary mode.
     with io.open(filename, 'wb') as f:
-        pofile.write_po(f, catalog, line_width)
+        pofile.write_po(f, catalog, **kwargs)
 
 
-def write_mo(filename, catalog):
+def write_mo(filename, catalog, **kwargs):
     """write mo file from catalog object
 
     :param unicode filename: path to mo file
@@ -51,7 +61,7 @@ def write_mo(filename, catalog):
     if not os.path.exists(dirname):
         os.makedirs(dirname)
     with io.open(filename, 'wb') as f:
-        mofile.write_mo(f, catalog)
+        mofile.write_mo(f, catalog, **kwargs)
 
 
 def translated_entries(catalog):
diff --git a/sphinx_intl/commands.py b/sphinx_intl/commands.py
index fb378f1..3567cc5 100644
--- a/sphinx_intl/commands.py
+++ b/sphinx_intl/commands.py
@@ -130,6 +130,12 @@ def convert(self, value, param, ctx):
     help='The maximum line width for the po files, 0 or a negative number '
          'disable line wrapping')
 
+option_no_obsolete = click.option(
+    '--no-obsolete',
+    envvar=ENVVAR_PREFIX + '_NO_OBSOLETE',
+    is_flag=True, default=False,
+    help='Remove obsolete #~ messages.')
+
 option_transifex_token = click.option(
     '--transifex-token',
     envvar=ENVVAR_PREFIX + '_TRANSIFEX_TOKEN',
@@ -234,7 +240,8 @@ def main(ctx, config, tag):
 @option_pot_dir
 @option_language
 @option_line_width
-def update(locale_dir, pot_dir, language, line_width):
+@option_no_obsolete
+def update(locale_dir, pot_dir, language, line_width, no_obsolete):
     """
     Update specified language's po files from pot.
 
@@ -260,7 +267,7 @@ def update(locale_dir, pot_dir, language, line_width):
                % locals())
         raise click.BadParameter(msg, param_hint='language')
 
-    basic.update(locale_dir, pot_dir, languages, line_width)
+    basic.update(locale_dir, pot_dir, languages, line_width, ignore_obsolete=no_obsolete)
 
 
 @main.command()
diff --git a/tests/test_cmd_pot.py b/tests/test_cmd_pot.py
index 865a3b0..2ef062d 100644
--- a/tests/test_cmd_pot.py
+++ b/tests/test_cmd_pot.py
@@ -8,6 +8,9 @@
     :copyright: Copyright 2019 by Takayuki SHIMIZUKAWA.
     :license: BSD, see LICENSE for details.
 """
+
+import os
+
 from click.testing import CliRunner
 
 from sphinx_intl import commands
@@ -67,6 +70,83 @@ def test_update_difference_detect(temp):
     assert r4.output.count('Not Changed:') == 1
 
 
+def test_update_line_width(temp):
+    with open('_build/locale/README.pot', 'r') as f:
+        template = f.read()
+
+    with open('_build/locale/README.pot', 'w') as f:
+        f.write(template)
+        f.write('\nmsgid "foorbar identifier1"\nmsgstr ""\n')
+
+    po_dir = os.path.join('locale', 'ja', 'LC_MESSAGES')
+    po_file = os.path.join(po_dir, 'README.po')
+
+    r1 = runner.invoke(commands.update, ['-d', 'locale', '-p', '_build/locale', '-l', 'ja'])
+    assert r1.exit_code == 0
+
+    with open(po_file, 'r') as f:
+        contents = f.read()
+        assert '"foorbar identifier1"\n' in contents
+
+    # change the identifier to trigger an update and impose a lower line-width count
+    with open('_build/locale/README.pot', 'w') as f:
+        f.write(template)
+        f.write('\nmsgid "foorbar identifier2"\nmsgstr ""\n')
+
+    r2 = runner.invoke(commands.update, ['-d', 'locale', '-p', '_build/locale', '-w', '1'])
+    assert r2.exit_code == 0
+
+    with open(po_file, 'r') as f:
+        contents = f.read()
+        assert '"foorbar"\n' in contents
+        assert '"identifier2"\n' in contents
+
+
+def test_update_no_obsolete(temp):
+    with open('_build/locale/README.pot', 'r') as f:
+        template = f.read()
+
+    with open('_build/locale/README.pot', 'w') as f:
+        f.write(template)
+        f.write('\nmsgid "foorbar1"\nmsgstr ""\n')
+        f.write('\nmsgid "foorbar2"\nmsgstr ""\n')
+
+    po_dir = os.path.join('locale', 'ja', 'LC_MESSAGES')
+    po_file = os.path.join(po_dir, 'README.po')
+
+    r1 = runner.invoke(commands.update, ['-d', 'locale', '-p', '_build/locale', '-l', 'ja'])
+    assert r1.exit_code == 0
+
+    with open(po_file, 'r') as f:
+        contents = f.read()
+        assert '\nmsgid "foorbar1"\n' in contents
+        assert '\nmsgid "foorbar2"\n' in contents
+
+    # remove the foorbar2 and verify we can see the obsolete entry
+    with open('_build/locale/README.pot', 'w') as f:
+        f.write(template)
+        f.write('\nmsgid "foorbar1"\nmsgstr ""\n')
+
+    r2 = runner.invoke(commands.update, ['-d', 'locale', '-p', '_build/locale'])
+    assert r2.exit_code == 0
+
+    with open(po_file, 'r') as f:
+        contents = f.read()
+        assert '\n#~ msgid "foorbar2"\n' in contents
+
+    # remove the foorbar1 and verify we can no longer see any obsolete entry
+    with open('_build/locale/README.pot', 'w') as f:
+        f.write(template)
+
+    r3 = runner.invoke(commands.update, ['-d', 'locale', '-p', '_build/locale', '--no-obsolete'])
+    assert r3.exit_code == 0
+
+    with open(po_file, 'r') as f:
+        contents = f.read()
+        assert 'msgid "foorbar1"' not in contents
+        assert 'msgid "foorbar2"' not in contents
+
+
 def test_stat(temp):
     r1 = runner.invoke(commands.update, ['-d', 'locale', '-p', '_build/locale', '-l', 'ja'])
     assert r1.exit_code == 0