diff --git a/compose.override.yaml b/compose.override.yaml
index 2e5c91e..a0cb098 100644
--- a/compose.override.yaml
+++ b/compose.override.yaml
@@ -41,6 +41,7 @@ services:
         domainname: "${DOMAINNAME}"
         environment:
             <<: [ *common-grafana-variables, *common-mysql-variables, *common-redis-variables ]
+            MYSQL_PORT: "3306"
             OPSI_ADMIN_PASSWORD: "${OPSI_ADMIN_PASSWORD}"
             OPSI_ROOT_PASSWORD: "${OPSI_ROOT_PASSWORD}"
             OPSICONFD_LOG_LEVEL: "${OPSICONFD_LOG_LEVEL:-6}"