Installing via composer automatically installs typo3-ter/realurl

Hello everybody, I just tried to install this extension via composer with

require {
"typo3-ter/seo-basics": "^0.9.2"
}

As I have already installed helhum/realurl (folder typo3conf/ext/realurl) the composer update then installed typo3-ter/realurl in the same folder which obviously crashed the system. Unfortunately I could not find any dependency regarding realurl. There is only a suggest for realurl and cooluri in the composer.json of seo_basics. I do not understand why composer still tries to install another version of realurl and so I just manually downloaded seo_basics from this github repository and implemented it, which worked fine. But somehow this is not the right way to do it...

Could this be fixed somehow or am I doing something wrong?

Kind regards, Joachim Wetzel

My composer command line log after just adding the require line (see above) to composer.json:

me@dockercontainer:/var/www/cms# composer update
Do not run Composer as root/super user! See https://getcomposer.org/root for details
Loading composer repositories with package information
Updating dependencies (including require-dev)
Package operations: 2 installs, 0 updates, 0 removals
  - Installing typo3-ter/realurl (2.2.1): Loading from cache
  - Installing typo3-ter/seo-basics (0.9.2): Loading from cache
Writing lock file
Generating autoload files
Inserting TYPO3_COMPOSER_MODE constant

b13 / t3ext-seo_basics

Installing via composer automatically installs typo3-ter/realurl #60