diff --git a/docker-compose.yml b/docker-compose.yml
index 21b371c..85c5168 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -88,7 +88,7 @@ services:
         condition: service_completed_successfully
     networks:
       - internal
-      - proxy
+      - gateway-garmin
     healthcheck:
       test: ["CMD", "curl", "-f", "http://localhost:8000/ready"]
       interval: 30s
@@ -231,5 +231,6 @@ volumes:
 networks:
   internal:
     driver: bridge
-  proxy:
-    external: true  # must exist: docker network create proxy
+  gateway-garmin:
+    external: true
+    name: gateway-garmin
diff --git a/ml-service/src/models/sleep_metrics.py b/ml-service/src/models/sleep_metrics.py
index 3eecb35..dbffd3a 100644
--- a/ml-service/src/models/sleep_metrics.py
+++ b/ml-service/src/models/sleep_metrics.py
@@ -11,7 +11,7 @@ def _std_hours_circular(hours: list[float]) -> float:
     """
     if len(hours) < 2:
         return 0.0
-    angles = [h / 24.0 * 2 * math.pi for h in hours]
+    angles = [float(h) / 24.0 * 2 * math.pi for h in hours]
     sin_mean = sum(math.sin(a) for a in angles) / len(angles)
     cos_mean = sum(math.cos(a) for a in angles) / len(angles)
     R = math.sqrt(sin_mean**2 + cos_mean**2)