JPARepository in spring-boot maven multi-module application

My next application is a maven multi-module application with this structure:

main-app

model sub-project
service sub-project
front-end sub-project

In the model sub-project there are all entities for application domain, in service sub-project the are the Spring Boot Controller and RestController and front-end sub-project is a simple web application with thymeleaf template engine.

Now i've a question about JPARepository (from spring boot implementation) interfaces for entities! Where should this object be? In service or model sub-project?