diff --git a/wp1/models/wp10/category.py b/wp1/models/wp10/category.py
index 8ad570d8f..f07b5fedc 100644
--- a/wp1/models/wp10/category.py
+++ b/wp1/models/wp10/category.py
@@ -1,13 +1,14 @@
 import attr
+from typing import Optional
 
 
 @attr.s
 class Category:
     table_name = "categories"
 
-    c_project = attr.ib()
-    c_type = attr.ib()
-    c_rating = attr.ib()
-    c_replacement = attr.ib(default=None)
-    c_category = attr.ib(default=None)
-    c_ranking = attr.ib(default=None)
+    c_project: bytes = attr.ib()
+    c_type: bytes = attr.ib()
+    c_rating: bytes = attr.ib()
+    c_replacement: Optional[bytes] = attr.ib(default=None)
+    c_category: Optional[bytes] = attr.ib(default=None)
+    c_ranking: Optional[int] = attr.ib(default=None)
diff --git a/wp1/models/wp10/namespace.py b/wp1/models/wp10/namespace.py
index 4ac9e44e6..aabb91833 100644
--- a/wp1/models/wp10/namespace.py
+++ b/wp1/models/wp10/namespace.py
@@ -1,5 +1,5 @@
 import enum
-
+from typing import Optional
 import attr
 
 
@@ -13,8 +13,8 @@ class NsType(enum.Enum):
 class Namespace:
     table_name = "namespacename"
 
-    domain = attr.ib()
-    ns_name = attr.ib()
-    ns_type = attr.ib()
-    ns_id = attr.ib(default=None)
-    dbname = attr.ib(default=None)
+    domain: bytes = attr.ib()
+    ns_name: bytes = attr.ib()
+    ns_type: NsType = attr.ib()
+    ns_id: Optional[int] = attr.ib(default=None)
+    dbname: Optional[bytes] = attr.ib(default=None)
diff --git a/wp1/models/wp10/release.py b/wp1/models/wp10/release.py
index f584c1107..183ed13c4 100644
--- a/wp1/models/wp10/release.py
+++ b/wp1/models/wp10/release.py
@@ -5,6 +5,6 @@
 class Release:
     table_name = "releases"
 
-    rel_article = attr.ib()
-    rel_0p5_category = attr.ib()
-    rel_0p5_timestamp = attr.ib()
+    rel_article: bytes = attr.ib()
+    rel_0p5_category: bytes = attr.ib()
+    rel_0p5_timestamp: bytes = attr.ib()
diff --git a/wp1/models/wp10/review.py b/wp1/models/wp10/review.py
index 56b964b63..7b8c17b53 100644
--- a/wp1/models/wp10/review.py
+++ b/wp1/models/wp10/review.py
@@ -1,5 +1,6 @@
 from sqlalchemy import Column
 from sqlalchemy.dialects.mysql import BINARY
+from typing import Optional
 
 from wp1.wp10_db import Base
 
@@ -7,11 +8,11 @@
 class Review(Base):
     __tablename__ = "reviews"
 
-    value = Column("rev_value", BINARY(10))
-    article = Column("rev_article", BINARY(255), primary_key=True)
-    timestamp = Column("rev_timestamp", BINARY(20))
+    value: Optional[bytes] = Column("rev_value", BINARY(10))
+    article: bytes = Column("rev_article", BINARY(255), primary_key=True)
+    timestamp: Optional[bytes] = Column("rev_timestamp", BINARY(20))
 
-    def __repr__(self):
+    def __repr__(self) -> str:
         return "<Review(value=%r, article=%r, timestamp=%r)>" % (
             self.value,
             self.article,