In the context of semantic versioning, does a change in the default configuration warrant a new major version?

Question

My module is enabled by default (i.e. when you add the module). There's also a configuration you can optionally use, which supports an enabled="true|false" setting. This way the module can be disabled after it's been added, without the need to remove the module.

But I realized the module doesn't play nicely with another module that is also enabled by default. I am considering changing my module so it's not be enabled by default. This would break for anyone that has not explicitly enabled it with the enabled="true" configuration setting.

Should I wait for v2.0 for this? semver.org mentions the public API and breaking changes, not configuration. Is it generally accepted that configuration is part of the public API?