Comcast customers will see a boost in internet speeds, but reportedly there's a catch: They'll have to pay for both internet and TV service. 

Comcast said last week that it would be increasing the speeds of its Xfinity Internet service packages for millions of customers in Houston and the Oregon and southwest Washington areas. It said their download speeds would increase by 30 percent to 40 percent.

But only customers who bundle internet with cable TV and other services, and who have the company's latest X1 hardware, will have access to free speed increases, the Houston Chronicle reported on Tuesday.

Eligible customers will see some significant changes, though. Those with 60Mbps Internet download speeds will now experience 150Mbps; customers who currently have 150Mbps will have 250Mbps; and 250Mbps subscribers are being upgraded to either 400Mbps or 1Gbps, depending on the package.

Comcast boosted speeds for certain customers in January, but that wasn't restricted to people who bundle internet with cable TV. This'll be the first time the boost is restricted to cable TV subscribers. 

Comcast didn't immediately respond to a request for comment.  

More people are ditching cable and satellite TV as streaming takes over. In January, Comcast said it lost 33,000 traditional pay-TV subscribers in the fourth quarter of 2017 but gained 350,000 high-speed internet customers. Moves like this one could help combat the loss of customers.