diff --git a/projects/policyengine-api-simulation/src/modal/app.py b/projects/policyengine-api-simulation/src/modal/app.py
index b57666745..e2729c13a 100644
--- a/projects/policyengine-api-simulation/src/modal/app.py
+++ b/projects/policyengine-api-simulation/src/modal/app.py
@@ -144,6 +144,10 @@ def build_base_simulation_image() -> modal.Image:
             "fastapi>=0.115.0",
             "tables>=3.10.2",
             "logfire>=3.0.0",
+            # logfire imports importlib_metadata unconditionally but does
+            # not declare it as a dependency on Python 3.13, so install it
+            # explicitly or workers crash on ``import logfire``.
+            "importlib-metadata>=8",
             "policyengine-observability[fastapi]>=1.3.0,<2",
         )
         .run_commands(
diff --git a/projects/policyengine-api-simulation/src/modal/gateway/app.py b/projects/policyengine-api-simulation/src/modal/gateway/app.py
index e2a48825d..64144453e 100644
--- a/projects/policyengine-api-simulation/src/modal/gateway/app.py
+++ b/projects/policyengine-api-simulation/src/modal/gateway/app.py
@@ -29,6 +29,10 @@
         # the auth module at runtime here.
         "cryptography>=41.0.0",
         "logfire>=3.0.0",
+        # logfire imports importlib_metadata unconditionally but does not
+        # declare it as a dependency on Python 3.13, so install it
+        # explicitly or the container crashes at startup.
+        "importlib-metadata>=8",
         "policyengine-observability[fastapi]>=1.3.0,<2",
     )
     .add_local_python_source(
diff --git a/projects/policyengine-api-simulation/tests/test_modal_bundle_image.py b/projects/policyengine-api-simulation/tests/test_modal_bundle_image.py
index a41227f68..1bb8c7596 100644
--- a/projects/policyengine-api-simulation/tests/test_modal_bundle_image.py
+++ b/projects/policyengine-api-simulation/tests/test_modal_bundle_image.py
@@ -95,6 +95,10 @@ def test_modal_image_uses_policyengine_bundle_install(monkeypatch):
     packages = pip_install_calls[0][1]
     assert "policyengine-observability[fastapi]>=1.3.0,<2" in packages
     assert "logfire>=3.0.0" in packages
+    # logfire needs importlib_metadata at import time on Python 3.13 but
+    # does not declare it; without the explicit install every worker
+    # crashes on ``import logfire``.
+    assert "importlib-metadata>=8" in packages
 
     runtime_secret_sets = {
         name: kwargs["secrets"] for name, kwargs in app.app.function_calls
@@ -164,6 +168,9 @@ def test_gateway_image_installs_dual_observability(monkeypatch):
     packages = pip_install_calls[0][1]
     assert "policyengine-observability[fastapi]>=1.3.0,<2" in packages
     assert "logfire>=3.0.0" in packages
+    # Same importlib_metadata gap as the simulation image: without this the
+    # gateway ASGI factory dies in configure_logfire and every request 303s.
+    assert "importlib-metadata>=8" in packages
 
     function_kwargs = {name: kwargs for name, kwargs in app.app.function_calls}
     assert function_kwargs["web_app"]["secrets"] == [