diff --git a/tests/test_router_events.py b/tests/test_router_events.py
index b4c9bb4c41..10f3f69920 100644
--- a/tests/test_router_events.py
+++ b/tests/test_router_events.py
@@ -188,13 +188,33 @@ def test_router_nested_lifespan_state_discard_default_lifespan_app(
         state.sub_router_shutdown = True
 
     sub_router = APIRouter(lifespan=subrouter_lifespan)
+    sub_router_lifespan_ctx = sub_router.lifespan_context
 
     router = APIRouter(lifespan=router_lifespan)
+    router_lifespan_ctx = router.lifespan_context
     router.include_router(sub_router)
 
+    assert router.lifespan_context is not router_lifespan_ctx, (
+        "Including a sub-router with a lifespan should change the router's lifespan context"
+    )
+    assert router.lifespan_context is not sub_router_lifespan_ctx, (
+        "New router lifespan context should not be the same as the sub-router's lifespan context, since the router should merge the lifespan contexts of all included sub-routers"
+    )
+
     app = FastAPI()
+    app_lifespan_ctx = app.router.lifespan_context
     app.include_router(router)
 
+    assert app.router.lifespan_context is not app_lifespan_ctx, (
+        "Including a router with a lifespan should change the app's lifespan context"
+    )
+    assert app.router.lifespan_context is router.lifespan_context, (
+        "New app lifespan context should be the same as the router's lifespan context, since the app has a default lifespan"
+    )
+    assert app.router.lifespan_context is not sub_router_lifespan_ctx, (
+        "New app lifespan context should not be the same as the sub-router's lifespan context, since the app should merge the lifespan contexts of all included routers"
+    )
+
     @app.get("/")
     def main(request: Request) -> dict[str, str]:
         assert request.state.router
@@ -234,8 +254,13 @@ def test_router_nested_lifespan_state_discard_default_lifespan_child(
     router = APIRouter()
 
     app = FastAPI(lifespan=lifespan)
+    app_lifespan_ctx = app.router.lifespan_context
     app.include_router(router)
 
+    assert app.router.lifespan_context is app_lifespan_ctx, (
+        "Including a router without a lifespan should not change the app's lifespan context"
+    )
+
     @app.get("/")
     def main(request: Request) -> dict[str, str]:
         assert request.state.app
@@ -260,8 +285,13 @@ def test_router_nested_lifespan_state_no_lifespans(
     router = APIRouter()
 
     app = FastAPI()
+    app_lifespan_ctx = app.router.lifespan_context
     app.include_router(router)
 
+    assert app.router.lifespan_context is app_lifespan_ctx, (
+        "Including a router without a lifespan should not change the app's lifespan context"
+    )
+
     @app.get("/")
     def main(request: Request) -> dict[str, str]:
         return {"message": "Hello World"}