GitLab runner [Docker] Unable to register a runner for my self signed GitLab instance

My GitLab QA instance is using self signed certificate. I want to setup a Docker runner in a seperate VM.
When i try to register the runner using the below command, it got failed with the below error message. Is it not possible to register a runner docker for self signed GitLab instance?

docker exec -it gitlab-runner gitlab-runner register

ERROR: Registering runner… failed runner=xzxxaxxg status=couldn’t execute POST against https://hostname/ci/api/v1/runners/register.json: Post https://hostname/ci/api/v1/runners/register.json: x509: certificate signed by unknown authority
PANIC: Failed to register this runner. Perhaps you are having network problems