diff --git a/maubot/db.py b/maubot/db.py
index 6a4f82b..6210bee 100644
--- a/maubot/db.py
+++ b/maubot/db.py
@@ -13,40 +13,15 @@
 #
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
-from typing import Type
-from sqlalchemy import (Column, String, Boolean, ForeignKey, Text, TypeDecorator)
+from sqlalchemy import Column, String, Boolean, ForeignKey, Text
 from sqlalchemy.orm import Query, scoped_session
 from sqlalchemy.ext.declarative import declarative_base
-import json
 
 from mautrix.types import UserID, FilterID, SyncToken, ContentURI
-from mautrix.client.api.types.util import Serializable
-
-from .command_spec import CommandSpec
 
 Base: declarative_base = declarative_base()
 
 
-def make_serializable_alchemy(serializable_type: Type[Serializable]):
-    class SerializableAlchemy(TypeDecorator):
-        impl = Text
-
-        @property
-        def python_type(self):
-            return serializable_type
-
-        def process_literal_param(self, value: Serializable, _) -> str:
-            return json.dumps(value.serialize()) if value is not None else None
-
-        def process_bind_param(self, value: Serializable, _) -> str:
-            return json.dumps(value.serialize()) if value is not None else None
-
-        def process_result_value(self, value: str, _) -> serializable_type:
-            return serializable_type.deserialize(json.loads(value)) if value is not None else None
-
-    return SerializableAlchemy
-
-
 class DBPlugin(Base):
     query: Query
     __tablename__ = "plugin"
@@ -78,20 +53,6 @@ class DBClient(Base):
     avatar_url: ContentURI = Column(String(255), nullable=False, default="")
 
 
-class DBCommandSpec(Base):
-    query: Query
-    __tablename__ = "command_spec"
-
-    plugin: str = Column(String(255),
-                         ForeignKey("plugin.id", onupdate="CASCADE", ondelete="CASCADE"),
-                         primary_key=True)
-    client: UserID = Column(String(255),
-                            ForeignKey("client.id", onupdate="CASCADE", ondelete="CASCADE"),
-                            primary_key=True)
-    spec: CommandSpec = Column(make_serializable_alchemy(CommandSpec), nullable=False)
-
-
 def init(session: scoped_session) -> None:
     DBPlugin.query = session.query_property()
     DBClient.query = session.query_property()
-    DBCommandSpec.query = session.query_property()