diff --git a/docker-compose.yml b/docker-compose.yml
index 58fafe9..5c30137 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -5,7 +5,11 @@ services:
     environment:
       KC_BOOTSTRAP_ADMIN_USERNAME: admin
       KC_BOOTSTRAP_ADMIN_PASSWORD: admin
-      KC_DB: dev-mem
+      # dev-file persists Keycloak's H2 DB under /opt/keycloak/data/h2/
+      # so the realm + test users survive container restarts. With the
+      # previous dev-mem the realm dissolved every time KC went idle,
+      # breaking local M7.1 smoke testing.
+      KC_DB: dev-file
       KC_HEALTH_ENABLED: "true"
     ports:
       - "8080:8080"
@@ -15,6 +19,7 @@ services:
     volumes:
       - ./keycloak/realm-export.json:/opt/keycloak/data/import/realm-export.json:ro
       - ./keycloak/themes/certifai:/opt/keycloak/themes/certifai:ro
+      - keycloak-data:/opt/keycloak/data/h2
     healthcheck:
       test: ["CMD-SHELL", "exec 3<>/dev/tcp/localhost/8080 && echo -e 'GET /realms/master HTTP/1.1\\r\\nHost: localhost\\r\\nConnection: close\\r\\n\\r\\n' >&3 && head -1 <&3 | grep -q '200 OK'"]
       interval: 10s
@@ -256,3 +261,4 @@ volumes:
   langfuse-db-data:
   langfuse-clickhouse-data:
   langfuse-clickhouse-logs:
+  keycloak-data: