diff --git a/fbchat/_core.py b/fbchat/_core.py
index 3f03a4b..fed25af 100644
--- a/fbchat/_core.py
+++ b/fbchat/_core.py
@@ -1,7 +1,6 @@
 import sys
 import attr
 import logging
-import aenum
 
 log = logging.getLogger("fbchat")
 
@@ -12,25 +11,6 @@ kw_only = sys.version_info[:2] > (3, 5)
 attrs_default = attr.s(slots=True, kw_only=kw_only)
 
 
-class Enum(aenum.Enum):
-    """Used internally to support enumerations"""
-
-    def __repr__(self):
-        # For documentation:
-        return "{}.{}".format(type(self).__name__, self.name)
-
-    @classmethod
-    def _extend_if_invalid(cls, value):
-        try:
-            return cls(value)
-        except ValueError:
-            log.warning(
-                "Failed parsing {.__name__}({!r}). Extending enum.".format(cls, value)
-            )
-            aenum.extend_enum(cls, "UNKNOWN_{}".format(value).upper(), value)
-            return cls(value)
-
-
 # Frozen, so that it can be used in sets
 @attr.s(frozen=True, slots=True, kw_only=kw_only)
 class Image:
diff --git a/fbchat/_message.py b/fbchat/_message.py
index f9807c7..6cefdc8 100644
--- a/fbchat/_message.py
+++ b/fbchat/_message.py
@@ -1,11 +1,12 @@
 import attr
+import enum
 from string import Formatter
-from ._core import log, attrs_default, Enum
+from ._core import log, attrs_default
 from . import _util, _session, _attachment, _location, _file, _quick_reply, _sticker
 from typing import Optional
 
 
-class EmojiSize(Enum):
+class EmojiSize(enum.Enum):
     """Used to specify the size of a sent emoji."""
 
     LARGE = "369239383222810"
diff --git a/fbchat/_plan.py b/fbchat/_plan.py
index 9eff6ac..3cfbf89 100644
--- a/fbchat/_plan.py
+++ b/fbchat/_plan.py
@@ -1,10 +1,11 @@
 import attr
 import datetime
-from ._core import attrs_default, Enum
+import enum
+from ._core import attrs_default
 from . import _exception, _util, _session
 
 
-class GuestStatus(Enum):
+class GuestStatus(enum.Enum):
     INVITED = 1
     GOING = 2
     DECLINED = 3
diff --git a/fbchat/_thread.py b/fbchat/_thread.py
index 990568c..628cb3e 100644
--- a/fbchat/_thread.py
+++ b/fbchat/_thread.py
@@ -2,12 +2,13 @@ import abc
 import attr
 import collections
 import datetime
-from ._core import attrs_default, Enum, Image
+import enum
+from ._core import attrs_default, Image
 from . import _util, _exception, _session, _graphql, _attachment, _file, _plan
 from typing import MutableMapping, Any, Iterable, Tuple, Optional
 
 
-class ThreadLocation(Enum):
+class ThreadLocation(enum.Enum):
     """Used to specify where a thread is located (inbox, pending, archived, other)."""
 
     INBOX = "INBOX"
diff --git a/pyproject.toml b/pyproject.toml
index f586ea2..50c5ea0 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -14,7 +14,6 @@ maintainer = "Mads Marquart"
 maintainer-email = "madsmtm@gmail.com"
 home-page = "https://github.com/carpedm20/fbchat/"
 requires = [
-    "aenum~=2.0",
     "attrs>=19.1",
     "requests~=2.19",
     "beautifulsoup4~=4.0",
diff --git a/tests/test_core.py b/tests/test_core.py
deleted file mode 100644
index a35404c..0000000
--- a/tests/test_core.py
+++ /dev/null
@@ -1,14 +0,0 @@
-import pytest
-from fbchat._core import Enum
-
-
-@pytest.mark.filterwarnings("ignore::DeprecationWarning")
-def test_enum_extend_if_invalid():
-    class TestEnum(Enum):
-        A = 1
-        B = 2
-
-    assert TestEnum._extend_if_invalid(1) == TestEnum.A
-    assert TestEnum._extend_if_invalid(3) == TestEnum.UNKNOWN_3
-    assert TestEnum._extend_if_invalid(3) == TestEnum.UNKNOWN_3
-    assert TestEnum(3) == TestEnum.UNKNOWN_3