diff --git a/pyserve/_wsgi_wrapper.py b/pyserve/_wsgi_wrapper.py
index e5d0168..d2af9de 100644
--- a/pyserve/_wsgi_wrapper.py
+++ b/pyserve/_wsgi_wrapper.py
@@ -11,7 +11,9 @@ The WSGI app path is passed via environment variables:
 
 import importlib
 import os
-from typing import Any, Callable
+from typing import Any, Callable, Optional
+
+WSGI_ADAPTER: Optional[str] = None
 
 try:
     from a2wsgi import WSGIMiddleware
@@ -27,7 +29,7 @@ except ImportError:
         WSGI_ADAPTER = None
 
 
-def _load_wsgi_app() -> Callable:
+def _load_wsgi_app() -> Callable[..., Any]:
     app_path = os.environ.get("PYSERVE_WSGI_APP")
     is_factory = os.environ.get("PYSERVE_WSGI_FACTORY", "0") == "1"
 
@@ -51,8 +53,9 @@ def _load_wsgi_app() -> Callable:
         raise RuntimeError(f"Module '{module_name}' has no attribute '{attr_name}'")
 
     if is_factory:
-        return app_or_factory()
-    return app_or_factory
+        result: Callable[..., Any] = app_or_factory()
+        return result
+    return app_or_factory  # type: ignore[return-value]
 
 
 def _create_asgi_app() -> Any:
diff --git a/pyserve/extensions.py b/pyserve/extensions.py
index cba5bdb..e099956 100644
--- a/pyserve/extensions.py
+++ b/pyserve/extensions.py
@@ -223,7 +223,7 @@ class ExtensionManager:
         try:
             from .process_extension import ProcessOrchestrationExtension
 
-            self.extension_registry["process_orchestration"] = ProcessOrchestrationExtension  # type: ignore
+            self.extension_registry["process_orchestration"] = ProcessOrchestrationExtension
         except ImportError:
             pass  # Optional dependency
 
diff --git a/pyserve/server.py b/pyserve/server.py
index f1ae8e7..0e037c0 100644
--- a/pyserve/server.py
+++ b/pyserve/server.py
@@ -152,9 +152,10 @@ class PyServeServer:
 
     def _create_app(self) -> None:
         from contextlib import asynccontextmanager
+        from typing import AsyncIterator
 
         @asynccontextmanager
-        async def lifespan(app: Starlette):
+        async def lifespan(app: Starlette) -> AsyncIterator[None]:
             await self._load_async_extensions()
             logger.info("Async extensions loaded")
             yield