diff --git a/README.rst b/README.rst
index 5dd11a1a..f9be191d 100644
--- a/README.rst
+++ b/README.rst
@@ -90,7 +90,7 @@ Key features of the ``Dependency Injector``:
        api_client = providers.Singleton(
            ApiClient,
            api_key=config.api_key,
-           timeout=config.timeout.as_int(),
+           timeout=config.timeout,
        )
 
        service = providers.Factory(
@@ -106,8 +106,8 @@ Key features of the ``Dependency Injector``:
 
    if __name__ == "__main__":
        container = Container()
-       container.config.api_key.from_env("API_KEY")
-       container.config.timeout.from_env("TIMEOUT")
+       container.config.api_key.from_env("API_KEY", required=True)
+       container.config.timeout.from_env("TIMEOUT", as_=int, default=5)
        container.wire(modules=[__name__])
 
        main()  # <-- dependency is injected automatically
diff --git a/docs/index.rst b/docs/index.rst
index afbee51e..6ff500d1 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -96,7 +96,7 @@ Key features of the ``Dependency Injector``:
        api_client = providers.Singleton(
            ApiClient,
            api_key=config.api_key,
-           timeout=config.timeout.as_int(),
+           timeout=config.timeout,
        )
 
        service = providers.Factory(
@@ -112,8 +112,8 @@ Key features of the ``Dependency Injector``:
 
    if __name__ == "__main__":
        container = Container()
-       container.config.api_key.from_env("API_KEY")
-       container.config.timeout.from_env("TIMEOUT")
+       container.config.api_key.from_env("API_KEY", required=True)
+       container.config.timeout.from_env("TIMEOUT", as_=int, default=5)
        container.wire(modules=[__name__])
 
        main()  # <-- dependency is injected automatically
diff --git a/docs/introduction/di_in_python.rst b/docs/introduction/di_in_python.rst
index 7c1a3cfd..f19a6c26 100644
--- a/docs/introduction/di_in_python.rst
+++ b/docs/introduction/di_in_python.rst
@@ -172,7 +172,7 @@ the dependency.
        api_client = providers.Singleton(
            ApiClient,
            api_key=config.api_key,
-           timeout=config.timeout.as_int(),
+           timeout=config.timeout,
        )
 
        service = providers.Factory(
@@ -188,8 +188,8 @@ the dependency.
 
    if __name__ == "__main__":
        container = Container()
-       container.config.api_key.from_env("API_KEY")
-       container.config.timeout.from_env("TIMEOUT")
+       container.config.api_key.from_env("API_KEY", required=True)
+       container.config.timeout.from_env("TIMEOUT", as_=int, default=5)
        container.wire(modules=[__name__])
 
        main()  # <-- dependency is injected automatically
diff --git a/examples/demo/with_di.py b/examples/demo/with_di.py
index 9cb51e16..bf154976 100644
--- a/examples/demo/with_di.py
+++ b/examples/demo/with_di.py
@@ -13,7 +13,7 @@ class Container(containers.DeclarativeContainer):
     api_client = providers.Singleton(
         ApiClient,
         api_key=config.api_key,
-        timeout=config.timeout.as_int(),
+        timeout=config.timeout,
     )
 
     service = providers.Factory(
@@ -29,8 +29,8 @@ def main(service: Service = Provide[Container.service]):
 
 if __name__ == "__main__":
     container = Container()
-    container.config.api_key.from_env("API_KEY")
-    container.config.timeout.from_env("TIMEOUT")
+    container.config.api_key.from_env("API_KEY", required=True)
+    container.config.timeout.from_env("TIMEOUT", as_=int, default=5)
     container.wire(modules=[__name__])
 
     main()  # <-- dependency is injected automatically