README.md in opentelemetry-propagator-b3-0.12.0 vs README.md in opentelemetry-propagator-b3-0.13.0

@@ -37,10 +37,10 @@
 The `opentelemetry-propagator-b3` gem is distributed under the Apache 2.0 license. See [LICENSE][license-github] for more information.
 
 [opentelemetry-home]: https://opentelemetry.io
 [bundler-home]: https://bundler.io
 [repo-github]: https://github.com/open-telemetry/opentelemetry-ruby
-[license-github]: https://github.com/open-telemetry/opentelemetry-ruby/blob/master/LICENSE
+[license-github]: https://github.com/open-telemetry/opentelemetry-ruby/blob/main/LICENSE
 [ruby-sig]: https://github.com/open-telemetry/community#ruby-sig
 [community-meetings]: https://github.com/open-telemetry/community#community-meetings
 [ruby-gitter]: https://gitter.im/open-telemetry/opentelemetry-ruby
 [b3-spec]: https://github.com/openzipkin/b3-propagation