diff --git a/dev_data.py b/dev_data.py
index b33233c5..0ff3448f 100755
--- a/dev_data.py
+++ b/dev_data.py
@@ -31,13 +31,13 @@ def main() -> None:
 
             un1 = Username(
                 user_id=user.id,
-                _username=data["username"],
+                _username=data["username"],  # type: ignore
                 is_primary=True,
                 show_in_directory=True,
             )
             un2 = Username(
                 user_id=user.id,
-                _username=data["username"] + "-alias",
+                _username=data["username"] + "-alias",  # type: ignore
                 is_primary=False,
                 show_in_directory=True,
             )
diff --git a/hushline/model.py b/hushline/model.py
index 096ce077..63d89a2d 100644
--- a/hushline/model.py
+++ b/hushline/model.py
@@ -68,6 +68,16 @@ class Username(Model):
     extra_field_verified3: Mapped[Optional[bool]] = mapped_column(default=False)
     extra_field_verified4: Mapped[Optional[bool]] = mapped_column(default=False)
 
+    def __init__(
+        self,
+        _username: str,
+        is_primary: bool,
+        **kwargs: Any,
+    ) -> None:
+        super().__init__(**kwargs)
+        self._username = _username
+        self.is_primary = is_primary
+
     @property
     def username(self) -> str:
         return self._username
@@ -258,10 +268,9 @@ class Message(Model):
     username_id: Mapped[int] = mapped_column(db.ForeignKey("usernames.id"))
     username: Mapped["Username"] = relationship(uselist=False)
 
-    def __init__(self, **kwargs: Any) -> None:
+    def __init__(self, content: str, **kwargs: Any) -> None:
         if "_content" in kwargs:
             raise ValueError("Cannot set '_content' directly. Use 'content'")
-        content = kwargs.pop("content", None)
         super().__init__(**kwargs)
         self.content = content
 
diff --git a/hushline/routes.py b/hushline/routes.py
index fe760025..f2b50f01 100644
--- a/hushline/routes.py
+++ b/hushline/routes.py
@@ -364,7 +364,7 @@ def register() -> Response | str | tuple[Response | str, int]:
             db.session.add(user)
             db.session.flush()
 
-            username = Username(username=username, user_id=user.id, is_primary=True)
+            username = Username(_username=username, user_id=user.id, is_primary=True)
             db.session.add(username)
             db.session.commit()
 
diff --git a/hushline/settings/__init__.py b/hushline/settings/__init__.py
index 92eed2ae..5e383710 100644
--- a/hushline/settings/__init__.py
+++ b/hushline/settings/__init__.py
@@ -246,7 +246,7 @@ async def index() -> str | Response:
         ).all()
         # Additional admin-specific data initialization
         user_count = two_fa_count = pgp_key_count = two_fa_percentage = pgp_key_percentage = None
-        all_users = []
+        all_users: list[User] = []
 
         # Check if user is admin and add admin-specific data
         if user.is_admin:
@@ -260,7 +260,6 @@ async def index() -> str | Response:
                     .filter(User._pgp_key != "")
                 )
             )
-            user_count = len(all_users)
             two_fa_percentage = (two_fa_count / user_count * 100) if user_count else 0
             pgp_key_percentage = (pgp_key_count / user_count * 100) if user_count else 0
             all_users = list(
@@ -268,6 +267,7 @@ async def index() -> str | Response:
                     db.select(User).join(Username).order_by(Username._username)
                 ).all()
             )
+            user_count = len(all_users)
 
         # Prepopulate form fields
         email_forwarding_form.forwarding_enabled.data = user.email is not None
@@ -343,7 +343,9 @@ def change_password() -> str | Response:
             flash("New password is invalid.")
             return redirect(url_for("settings.index"))
 
-        if not user.check_password(change_password_form.old_password.data):
+        if not change_password_form.old_password.data or not user.check_password(
+            change_password_form.old_password.data
+        ):
             flash("Incorrect old password.", "error")
             return redirect(url_for("settings.index"))
 
@@ -503,7 +505,7 @@ def update_pgp_key() -> Response | str:
         if form.validate_on_submit():
             pgp_key = form.pgp_key.data
 
-            if pgp_key.strip() == "":
+            if pgp_key is None or pgp_key.strip() == "":
                 # If the field is empty, remove the PGP key
                 user.pgp_key = None
                 user.email = None  # remove the forwarding email if the PGP key is removed
diff --git a/tests/auth_helper.py b/tests/auth_helper.py
index 6f589f3b..1b5d47b5 100644
--- a/tests/auth_helper.py
+++ b/tests/auth_helper.py
@@ -91,10 +91,8 @@ def login_user(client: FlaskClient, username: str, password: str) -> User | None
         f'href="/inbox?username={username}"'.encode() in response.data
     ), f"Inbox link should be present for the user {username}"
 
-    if username := db.session.scalars(
-        db.select(Username).filter_by(_username=username)
-    ).one_or_none():
-        return username.user
+    if uname := db.session.scalars(db.select(Username).filter_by(_username=username)).one_or_none():
+        return uname.user
     return None