diff --git a/pymodmilter/__init__.py b/pymodmilter/__init__.py
index 3753dc5..48d01f1 100644
--- a/pymodmilter/__init__.py
+++ b/pymodmilter/__init__.py
@@ -22,105 +22,19 @@ __all__ = [
 
 __version__ = "1.1.4"
 
+import _runtime_patches
+
 import Milter
 import logging
-import encodings
 
 from Milter.utils import parse_addr
+
 from email.message import MIMEPart
 from email.parser import BytesFeedParser
 from email.policy import default as default_policy
 
 from pymodmilter.conditions import Conditions
 
-########################################################
-#  monkey-patch pythons email library bug 27257,30988  #
-########################################################
-#
-# https://bugs.python.org/issue27257
-# https://bugs.python.org/issue30988
-#
-# fix: https://github.com/python/cpython/pull/15600
-
-import email._header_value_parser
-from email._header_value_parser import TokenList, NameAddr
-from email._header_value_parser import get_display_name, get_angle_addr
-from email._header_value_parser import get_cfws, errors
-from email._header_value_parser import CFWS_LEADER, PHRASE_ENDS
-
-
-class DisplayName(email._header_value_parser.DisplayName):
-    @property
-    def display_name(self):
-        res = TokenList(self)
-        if len(res) == 0:
-            return res.value
-        if res[0].token_type == 'cfws':
-            res.pop(0)
-        else:
-            if isinstance(res[0], TokenList) and \
-                    res[0][0].token_type == 'cfws':
-                res[0] = TokenList(res[0][1:])
-        if res[-1].token_type == 'cfws':
-            res.pop()
-        else:
-            if isinstance(res[-1], TokenList) and \
-                    res[-1][-1].token_type == 'cfws':
-                res[-1] = TokenList(res[-1][:-1])
-        return res.value
-
-
-def get_name_addr(value):
-    """ name-addr = [display-name] angle-addr
-
-    """
-    name_addr = NameAddr()
-    # Both the optional display name and the angle-addr can start with cfws.
-    leader = None
-    if value[0] in CFWS_LEADER:
-        leader, value = get_cfws(value)
-        if not value:
-            raise errors.HeaderParseError(
-                "expected name-addr but found '{}'".format(leader))
-    if value[0] != '<':
-        if value[0] in PHRASE_ENDS:
-            raise errors.HeaderParseError(
-                "expected name-addr but found '{}'".format(value))
-        token, value = get_display_name(value)
-        if not value:
-            raise errors.HeaderParseError(
-                "expected name-addr but found '{}'".format(token))
-        if leader is not None:
-            if isinstance(token[0], TokenList):
-                token[0][:0] = [leader]
-            else:
-                token[:0] = [leader]
-            leader = None
-        name_addr.append(token)
-    token, value = get_angle_addr(value)
-    if leader is not None:
-        token[:0] = [leader]
-    name_addr.append(token)
-    return name_addr, value
-
-
-setattr(email._header_value_parser, "DisplayName", DisplayName)
-setattr(email._header_value_parser, "get_name_addr", get_name_addr)
-
-################################################
-#  add charset alias for windows-874 encoding  #
-################################################
-
-aliases = encodings.aliases.aliases
-
-for alias in ["windows-874", "windows_874"]:
-    if alias not in aliases:
-        aliases[alias] = "cp874"
-
-setattr(encodings.aliases, "aliases", aliases)
-
-################################################
-
 
 class CustomLogger(logging.LoggerAdapter):
     def process(self, msg, kwargs):
diff --git a/pymodmilter/_runtime_patches.py b/pymodmilter/_runtime_patches.py
new file mode 100644
index 0000000..b1a9ad8
--- /dev/null
+++ b/pymodmilter/_runtime_patches.py
@@ -0,0 +1,107 @@
+# PyMod-Milter is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# PyMod-Milter is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with PyMod-Milter.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+import encodings
+
+
+#####################################
+#    patch pythons email library    #
+#####################################
+#
+# https://bugs.python.org/issue27257
+# https://bugs.python.org/issue30988
+#
+# fix: https://github.com/python/cpython/pull/15600
+
+import email._header_value_parser
+from email._header_value_parser import TokenList, NameAddr
+from email._header_value_parser import get_display_name, get_angle_addr
+from email._header_value_parser import get_cfws, errors
+from email._header_value_parser import CFWS_LEADER, PHRASE_ENDS
+
+
+class DisplayName(email._header_value_parser.DisplayName):
+    @property
+    def display_name(self):
+        res = TokenList(self)
+        if len(res) == 0:
+            return res.value
+        if res[0].token_type == 'cfws':
+            res.pop(0)
+        else:
+            if isinstance(res[0], TokenList) and \
+                    res[0][0].token_type == 'cfws':
+                res[0] = TokenList(res[0][1:])
+        if res[-1].token_type == 'cfws':
+            res.pop()
+        else:
+            if isinstance(res[-1], TokenList) and \
+                    res[-1][-1].token_type == 'cfws':
+                res[-1] = TokenList(res[-1][:-1])
+        return res.value
+
+
+def get_name_addr(value):
+    """ name-addr = [display-name] angle-addr
+
+    """
+    name_addr = NameAddr()
+    # Both the optional display name and the angle-addr can start with cfws.
+    leader = None
+    if value[0] in CFWS_LEADER:
+        leader, value = get_cfws(value)
+        if not value:
+            raise errors.HeaderParseError(
+                "expected name-addr but found '{}'".format(leader))
+    if value[0] != '<':
+        if value[0] in PHRASE_ENDS:
+            raise errors.HeaderParseError(
+                "expected name-addr but found '{}'".format(value))
+        token, value = get_display_name(value)
+        if not value:
+            raise errors.HeaderParseError(
+                "expected name-addr but found '{}'".format(token))
+        if leader is not None:
+            if isinstance(token[0], TokenList):
+                token[0][:0] = [leader]
+            else:
+                token[:0] = [leader]
+            leader = None
+        name_addr.append(token)
+    token, value = get_angle_addr(value)
+    if leader is not None:
+        token[:0] = [leader]
+    name_addr.append(token)
+    return name_addr, value
+
+
+setattr(email._header_value_parser, "DisplayName", DisplayName)
+setattr(email._header_value_parser, "get_name_addr", get_name_addr)
+
+
+#######################################
+#  add charset alias for windows-874  #
+#######################################
+#
+# https://bugs.python.org/issue17254
+#
+# fix: https://github.com/python/cpython/pull/10237
+
+aliases = encodings.aliases.aliases
+
+for alias in ["windows-874", "windows_874"]:
+    if alias not in aliases:
+        aliases[alias] = "cp874"
+
+setattr(encodings.aliases, "aliases", aliases)