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# HTTPS Certificates

Added in version 1.3.

By default, pip will perform SSL certificate verification for network connections it makes over HTTPS. These serve to prevent man-in-the-middle attacks against package downloads.

## Using a specific certificate store

The `--cert` option (and the corresponding `PIP_CERT` environment variable) allow users to specify a different certificate store/bundle for pip to use. It is also possible to use `REQUESTS_CA_BUNDLE` or `CURL_CA_BUNDLE` environment variables.

## Using system certificate stores

Added in version 24.2.

Note

Versions of pip prior to v24.2 did not use system certificates by default. To use system certificates with pip v22.2 or later, you must opt-in using the `--use-feature=truststore` CLI flag.

On Python 3.10 or later, by default system certificates are used in addition to certifi to verify HTTPS connections. This functionality is provided through the truststore package.

If you encounter a TLS/SSL error when using the `truststore` feature you should open an issue on the truststore GitHub issue tracker instead of pip’s issue tracker. The maintainers of truststore will help diagnose and fix the issue.

To opt-out of using system certificates you can pass the `--use-deprecated=legacy-certs` flag to pip.

Warning

On Python 3.9 or earlier, only certifi is used to verify HTTPS connections as `truststore` requires Python 3.10 or higher to function.

The system certificate store won’t be used in this case, so some situations like proxies with their own certificates may not work. Upgrading to at least Python 3.10 or later is the recommended method to resolve this issue.