diff --git a/reflex/config.pyi b/reflex/config.pyi
index ccaa6381a..497ce3eb4 100644
--- a/reflex/config.pyi
+++ b/reflex/config.pyi
@@ -96,7 +96,7 @@ class Config(Base):
         rxdeploy_url: Optional[str] = None,
         cp_backend_url: Optional[str] = None,
         cp_web_url: Optional[str] = None,
-        npm_prefer_offline: bool=False,
+        npm_prefer_offline: bool = False,
         username: Optional[str] = None,
         gunicorn_worker_class: Optional[str] = None,
         **kwargs
diff --git a/reflex/utils/prerequisites.py b/reflex/utils/prerequisites.py
index b7927ac09..f6261272f 100644
--- a/reflex/utils/prerequisites.py
+++ b/reflex/utils/prerequisites.py
@@ -517,9 +517,11 @@ def install_frontend_packages(packages: set[str]):
     config = get_config()
     package_manager = get_install_package_manager()
 
-    uses_npm = package_manager.endswith("npm")
+    uses_npm = package_manager.endswith("npm") if package_manager else False
 
-    prefer_offline = (["--prefer-offline"] if config.npm_prefer_offline and uses_npm else [])
+    prefer_offline = (
+        ["--prefer-offline"] if config.npm_prefer_offline and uses_npm else []
+    )
 
     # Install the base packages.
     process = processes.new_process(
@@ -696,8 +698,8 @@ def check_schema_up_to_date():
     with model.Model.get_db_engine().connect() as connection:
         try:
             if model.Model.alembic_autogenerate(
-                    connection=connection,
-                    write_migration_scripts=False,
+                connection=connection,
+                write_migration_scripts=False,
             ):
                 console.error(
                     "Detected database schema changes. Run [bold]reflex db makemigrations[/bold] "