diff --git a/docker-compose.yml b/docker-compose.yml
index 8c58caee..adc7bbb5 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -112,6 +112,10 @@ services:
     ports:
     - "127.0.0.1:8000:8000"
     restart: unless-stopped
+    ulimits:
+      nofile:
+        soft: 65535
+        hard: 65535
     user: ${UID:-1000}:${GID:-1000}
     volumes:
     - ${POLYWEATHER_RUNTIME_DATA_DIR:-/var/lib/polyweather}:/var/lib/polyweather
diff --git a/tests/test_deployment_runtime_config.py b/tests/test_deployment_runtime_config.py
index ffb55254..74d9fc80 100644
--- a/tests/test_deployment_runtime_config.py
+++ b/tests/test_deployment_runtime_config.py
@@ -149,6 +149,19 @@ def test_docker_compose_keeps_polyweather_ports_on_loopback():
     assert "\n    - 8000:8000" not in compose
 
 
+def test_web_container_raises_open_file_limit_for_sse_and_proxy_load():
+    compose = (ROOT / "docker-compose.yml").read_text(encoding="utf-8")
+    web_block = compose.split("  polyweather_web:", 1)[1].split(
+        "\nx-polyweather-base:",
+        1,
+    )[0]
+
+    assert "ulimits:" in web_block
+    assert "nofile:" in web_block
+    assert "soft: 65535" in web_block
+    assert "hard: 65535" in web_block
+
+
 def test_city_detail_builds_deb_hourly_consensus_before_peak_window():
     source = (ROOT / "web" / "analysis_service.py").read_text(encoding="utf-8")