diff --git a/src/flask_digest_auth/auth.py b/src/flask_digest_auth/auth.py
index fb10b6e..e4d0c54 100644
--- a/src/flask_digest_auth/auth.py
+++ b/src/flask_digest_auth/auth.py
@@ -344,50 +344,57 @@ class DigestAuth:
             self.realm = app.config["DIGEST_AUTH_REALM"]
 
         if hasattr(app, "login_manager"):
-            from flask_login import LoginManager, login_user
+            self.__init_login_manager(app)
 
-            login_manager: LoginManager = getattr(app, "login_manager")
+    def __init_login_manager(self, app: Flask) -> None:
+        """Initializes the Flask-Login login manager.
 
-            @login_manager.unauthorized_handler
-            def unauthorized() -> None:
-                """Handles when the user is unauthorized.
+        :param app: The Flask application.
+        :return: None.
+        """
+        from flask_login import LoginManager, login_user
+        login_manager: LoginManager = getattr(app, "login_manager")
 
-                :return: None.
-                """
-                state: AuthState = getattr(request, "_digest_auth_state") \
-                    if hasattr(request, "_digest_auth_state") \
-                    else AuthState()
-                response: Response = Response()
-                response.status = 401
-                response.headers["WWW-Authenticate"] \
-                    = self.__make_response_header(state)
-                abort(response)
+        @login_manager.unauthorized_handler
+        def unauthorized() -> None:
+            """Handles when the user is unauthorized.
 
-            @login_manager.request_loader
-            def load_user_from_request(req: Request) -> Optional[Any]:
-                """Loads the user from the request header.
+            :return: None.
+            """
+            state: AuthState = getattr(request, "_digest_auth_state") \
+                if hasattr(request, "_digest_auth_state") \
+                else AuthState()
+            response: Response = Response()
+            response.status = 401
+            response.headers["WWW-Authenticate"] \
+                = self.__make_response_header(state)
+            abort(response)
 
-                :param req: The request.
-                :return: The authenticated user, or None if the
-                    authentication fails
-                """
-                request._digest_auth_state = AuthState()
-                authorization: Authorization = req.authorization
-                try:
-                    if authorization is None:
-                        raise UnauthorizedException
-                    if authorization.type != "digest":
-                        raise UnauthorizedException(
-                            "Not an HTTP digest authorization")
-                    self.__authenticate(request._digest_auth_state)
-                    user = login_manager.user_callback(authorization.username)
-                    login_user(user)
-                    self.__on_login(user)
-                    return user
-                except UnauthorizedException as e:
-                    if str(e) != "":
-                        app.logger.warning(str(e))
-                    return None
+        @login_manager.request_loader
+        def load_user_from_request(req: Request) -> Optional[Any]:
+            """Loads the user from the request header.
+
+            :param req: The request.
+            :return: The authenticated user, or None if the
+                authentication fails
+            """
+            request._digest_auth_state = AuthState()
+            authorization: Authorization = req.authorization
+            try:
+                if authorization is None:
+                    raise UnauthorizedException
+                if authorization.type != "digest":
+                    raise UnauthorizedException(
+                        "Not an HTTP digest authorization")
+                self.__authenticate(request._digest_auth_state)
+                user = login_manager.user_callback(authorization.username)
+                login_user(user)
+                self.__on_login(user)
+                return user
+            except UnauthorizedException as e:
+                if str(e) != "":
+                    app.logger.warning(str(e))
+                return None
 
     def logout(self) -> None:
         """Logs out the user.