# OpenZeppelin Contracts issues reported by Slither **URL:** \ **Category:** Contracts\ **Tags:** erc20, audit, openzeppelin-contracts\ **Created:** [January 22, 2021, 5:49pm UTC](https://forum.openzeppelin.com/t/openzeppelin-contracts-issues-reported-by-slither/5518 "2021-01-22T17:49:30Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![dmdv](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.openzeppelin.com/dmdv/32/3862_2.png) [@dmdv](https://forum.openzeppelin.com/u/dmdv)\ **Post date:** [January 22, 2021, 5:49pm UTC](https://forum.openzeppelin.com/t/openzeppelin-contracts-issues-reported-by-slither/5518/1 "2021-01-22T17:49:30Z")
The question to openzeppeling team I use openzeppeling-contracts 3.0 Initializable, ERC20PresetMinterPauserUpgradeable, OwnableUpgradeable ![image](https://us1.discourse-cdn.com/flex022/uploads/zeppelin/original/2X/f/fd42b50d276e08bc1bdc271d9837e93ef6116b57.png) Slither analysis gives many issues from critical to medium ![image](https://us1.discourse-cdn.com/flex022/uploads/zeppelin/original/2X/f/f78ae3f8dab49eb45735f0ee3142653cb770ccf5.png) And compilation warnings: ![image](https://us1.discourse-cdn.com/flex022/uploads/zeppelin/original/2X/0/036857d7c4c42d332ff63f96d36cee8c96739956.png) Do I need to bother? Is it audited at all? ---
**Author:** ![abcoathup](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.openzeppelin.com/abcoathup/32/415_2.png) [@abcoathup](https://forum.openzeppelin.com/u/abcoathup)\ **Post date:** [January 25, 2021, 1:30am UTC](https://forum.openzeppelin.com/t/openzeppelin-contracts-issues-reported-by-slither/5518/2 "2021-01-25T01:30:05Z")
Hi @dmdv, Slither is reporting that the reserved storage gap `__gap` shadows the other gaps in inherited contracts. For information on the gap please see the following: [https://docs.openzeppelin.com/contracts/3.x/upgradeable#storage\_gaps](https://docs.openzeppelin.com/contracts/3.x/upgradeable#storage_gaps) As the storage gap is only used to reserve space I don't think shadowing is an issue. > [@dmdv](#): > > And compilation warnings: I assume you are compiling with Solidity 0.7. In Solidity 0.7 visibility ( `public` / `external` ) is not needed for constructors anymore. See: [https://docs.soliditylang.org/en/v0.8.0/070-breaking-changes.html#functions-and-events](https://docs.soliditylang.org/en/v0.8.0/070-breaking-changes.html#functions-and-events) > If you want to use Solidity 0.7, you may prefer to install `@openzeppelin/contracts@solc-0.7` > For the combination of upgradeable contracts and Solidity 0.7, use `@openzeppelin/contracts-upgradeable@solc-0.7` > From: [OpenZeppelin Contracts 3.3](https://forum.openzeppelin.com/t/openzeppelin-contracts-3-3/4804) You appear to have a mix of upgradeable and non-upgradeable contracts. For upgradeable contracts you should use OpenZeppelin Contracts Upgradeable, see: [https://docs.openzeppelin.com/contracts/3.x/upgradeable](https://docs.openzeppelin.com/contracts/3.x/upgradeable) > [@dmdv](#): > > Do I need to bother? I would go through all of the reported issues/warnings and either resolve or decide why it doesn't need to be resolved. I would suggest documenting this for your community. > [@dmdv](#): > > Is it audited at all? Last full audit on v2.0.0, see: [https://github.com/OpenZeppelin/openzeppelin-contracts/tree/master/audit](https://github.com/OpenZeppelin/openzeppelin-contracts/tree/master/audit) ---
**Author:** ![frangio](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.openzeppelin.com/frangio/32/15251_2.png) [@frangio](https://forum.openzeppelin.com/u/frangio)\ **Post date:** [January 25, 2021, 1:46pm UTC](https://forum.openzeppelin.com/t/openzeppelin-contracts-issues-reported-by-slither/5518/3 "2021-01-25T13:46:09Z")
I believe the warning about the gap variables is a bug in Slither. There is no shadowing because the variables are private. Unless they consider that shadowing as well? @dmdv Do you want to report this to Slither or should we do it? ---
**Author:** ![frangio](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.openzeppelin.com/frangio/32/15251_2.png) [@frangio](https://forum.openzeppelin.com/u/frangio)\ **Post date:** [January 25, 2021, 1:47pm UTC](https://forum.openzeppelin.com/t/openzeppelin-contracts-issues-reported-by-slither/5518/4 "2021-01-25T13:47:37Z")
The warnings about unused function parameters are a nuisance, sorry about that. We have an issue to fix it. [https://github.com/OpenZeppelin/openzeppelin-contracts-upgradeable/issues/89](https://github.com/OpenZeppelin/openzeppelin-contracts-upgradeable/issues/89) ---
**Author:** ![marsxr](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.openzeppelin.com/marsxr/32/3233_2.png) [@marsxr](https://forum.openzeppelin.com/u/marsxr)\ **Post date:** [January 26, 2021, 10:32am UTC](https://forum.openzeppelin.com/t/openzeppelin-contracts-issues-reported-by-slither/5518/5 "2021-01-26T10:32:29Z")
> [@frangio](#): > > I believe the warning about the gap variables is a bug in Slither. Slither is an automated tool. That gives loads of indications. Your job as developer is to assess which warnings are actionable. Not all warnings need to be acted upon. ---
**Author:** ![dmdv](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.openzeppelin.com/dmdv/32/3862_2.png) [@dmdv](https://forum.openzeppelin.com/u/dmdv)\ **Post date:** [January 28, 2021, 8:50am UTC](https://forum.openzeppelin.com/t/openzeppelin-contracts-issues-reported-by-slither/5518/6 "2021-01-28T08:50:45Z")
I’ve fixed the gap warning by moving to the 0.7.0 solc version of openzeppeling contracts. But only this is remaining ![image](https://us1.discourse-cdn.com/flex022/uploads/zeppelin/original/2X/0/0a7cb061ee386634f9714724366ed4ea2ada4961.png) ---
**Author:** ![frangio](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.openzeppelin.com/frangio/32/15251_2.png) [@frangio](https://forum.openzeppelin.com/u/frangio)\ **Post date:** [January 28, 2021, 2:22pm UTC](https://forum.openzeppelin.com/t/openzeppelin-contracts-issues-reported-by-slither/5518/7 "2021-01-28T14:22:28Z")
That’s a compiler warning that we haven’t fixed yet. It’s nothing to worry about, but it is annoying.