diff --git a/.gitea/workflows/cd.yaml b/.gitea/workflows/cd.yaml
index 5fcaaf19..993f5f16 100644
--- a/.gitea/workflows/cd.yaml
+++ b/.gitea/workflows/cd.yaml
@@ -124,27 +124,24 @@ jobs:
           exit $PYTEST_EXIT
 
       # ── 整合測試 B5 (2026-04-10) ──────────────────────────────────────────
-      # DinD 環境: runner 是 container，compose sibling 的 published port 綁在 host
-      # 用 host docker bridge IP (172.17.0.1) + exposed port 15432 連 postgres
       - name: Integration Tests (B5 — 真實 DB)
         run: |
           cd apps/api
           docker compose -f docker-compose.test.yml up -d --wait
-          # schema 初始化 (exec stdin 不需要 volume)
           docker compose -f docker-compose.test.yml exec -T postgres-test \
             psql -U awoooi -d awoooi_test \
             < tests/integration/setup_test_schema.sql
-          # DinD: runner 連 sibling container 需走 host bridge → port 15432
-          # ip 指令在精簡 runner 環境可能不存在，改用 /proc/net/route
-          HOST_IP=$(awk '$2=="00000000"{printf "%d.%d.%d.%d\n",
-            "0x"substr($3,7,2)+0,"0x"substr($3,5,2)+0,
-            "0x"substr($3,3,2)+0,"0x"substr($3,1,2)+0}' /proc/net/route | head -1)
-          # fallback: docker0 bridge 慣例 IP
-          [ -z "$HOST_IP" ] && HOST_IP="172.17.0.1"
-          echo "host bridge IP: $HOST_IP"
-          TEST_DATABASE_URL="postgresql+asyncpg://awoooi:awoooi_test_2026@${HOST_IP}:15432/awoooi_test?ssl=disable" \
+          # 直接取 postgres container 的 IP，把 runner 加入同一網路
+          PG_CONTAINER=$(docker ps --filter name=postgres-test --format '{{.Names}}' | head -1)
+          PG_NETWORK=$(docker inspect "$PG_CONTAINER" --format '{{range $k,$v := .NetworkSettings.Networks}}{{$k}}{{end}}' | head -1)
+          PG_IP=$(docker inspect "$PG_CONTAINER" --format "{{(index .NetworkSettings.Networks \"$PG_NETWORK\").IPAddress}}")
+          echo "PG container=$PG_CONTAINER network=$PG_NETWORK ip=$PG_IP"
+          # runner 加入 compose 網路，直連 5432
+          docker network connect "$PG_NETWORK" "$(cat /etc/hostname)" 2>/dev/null || true
+          TEST_DATABASE_URL="postgresql+asyncpg://awoooi:awoooi_test_2026@${PG_IP}:5432/awoooi_test?ssl=disable" \
             /opt/api-venv/bin/pytest tests/integration/test_b5_core_flows.py -v --tb=short
           TEST_EXIT=$?
+          docker network disconnect "$PG_NETWORK" "$(cat /etc/hostname)" 2>/dev/null || true
           docker compose -f docker-compose.test.yml down -v 2>/dev/null || true
           exit $TEST_EXIT