# Activity definition support

**URL:** <https://community.temporal.io/t/activity-definition-support/8209>\
**Category:** Community Support\
**Tags:** java-sdk\
**Created:** [May 10, 2023, 10:16am UTC](https://community.temporal.io/t/activity-definition-support/8209 "2023-05-10T10:16:47Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![kiril](https://avatars.discourse-cdn.com/v4/letter/k/b2d939/32.png) [@kiril](https://community.temporal.io/u/kiril)\
**Post date:** [May 10, 2023, 10:16am UTC](https://community.temporal.io/t/activity-definition-support/8209/1 "2023-05-10T10:16:47Z")

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All data are SerDe into json object internally for regular java objects.

In case I would like to change my activity return type to void or any other. Any issues I can expect?

My guess Temporal should skip previously returned value and continue workflow as this value are not used workflow.

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**Author:** ![maxim](https://sea2.discourse-cdn.com/flex016/user_avatar/community.temporal.io/maxim/32/8_2.png) [@maxim](https://community.temporal.io/u/maxim)\
**Post date:** [May 13, 2023, 4:41pm UTC](https://community.temporal.io/t/activity-definition-support/8209/2 "2023-05-13T16:41:16Z")

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It is expected that multiple activity versions will be active during deployments. So it could lead to failures if return types are not compatible. We recommend returning a structure as an activity result and changing this structure fields in a backward compatible manner.