diff --git a/pgvector/bit.py b/pgvector/bit.py
index 26a9d8d..cecd180 100644
--- a/pgvector/bit.py
+++ b/pgvector/bit.py
@@ -62,9 +62,12 @@ def from_binary(cls, value):
 
     @classmethod
     def _to_db(cls, value):
+        if value is None:
+            return value 
+        
         if not isinstance(value, cls):
-            raise ValueError('expected bit')
-
+            value = cls(value)
+        
         return value.to_text()
 
     @classmethod
@@ -73,3 +76,9 @@ def _to_db_binary(cls, value):
             raise ValueError('expected bit')
 
         return value.to_binary()
+
+    @classmethod
+    def _from_db(cls, value):
+        if value is None or isinstance(value, cls): 
+            return value
+        return cls.from_text(value)
\ No newline at end of file
diff --git a/pgvector/sqlalchemy/bit.py b/pgvector/sqlalchemy/bit.py
index 1ea85c3..b5f64f2 100644
--- a/pgvector/sqlalchemy/bit.py
+++ b/pgvector/sqlalchemy/bit.py
@@ -1,6 +1,8 @@
+import asyncpg
+from sqlalchemy.dialects.postgresql.asyncpg import PGDialect_asyncpg
 from sqlalchemy.dialects.postgresql.base import ischema_names
 from sqlalchemy.types import UserDefinedType, Float
-
+from .. import Bit
 
 class BIT(UserDefinedType):
     cache_ok = True
diff --git a/tests/test_sqlalchemy.py b/tests/test_sqlalchemy.py
index c59c12e..6900e3a 100644
--- a/tests/test_sqlalchemy.py
+++ b/tests/test_sqlalchemy.py
@@ -605,7 +605,7 @@ async def test_bit(self, engine):
 
         async with async_session() as session:
             async with session.begin():
-                embedding = asyncpg.BitString('101') if engine == asyncpg_engine else '101'
+                embedding = '101'
                 session.add(Item(id=1, binary_embedding=embedding))
                 item = await session.get(Item, 1)
                 assert item.binary_embedding == embedding