Yes. A DNS leak is a privacy and anonymity threat that can allow your ISP to see and monitor your online activity even when you have a VPN tunnel established.
The TunnelBear's secure VPN service automatically ensures that all traffic from your computer, including DNS, is sent through the VPN tunnel as soon as it is established. Our servers handle all DNS requests. There are no additional steps required to “enable” DNS leak protection - you're already secure when you connect to our encrypted tunnels.
When you connect to TunnelBear and go on dnsleaktest.com (or a similar service/website), you'll only see one IP address reported back to you in the results. This IP address should match the IP address of the VPN server you're currently connected to. To make sure, head over to our website and compare the results shown there with that of the DNS leak test. If the IPs match, then your DNS is not leaking.
Also, take a look at our blog post which goes into more detail about DNS and how TunnelBear handles it!