Specify version of imported package (GitHub) R Description File

In writing the Description file for an R package I wanted to specify a specific version of imported package that is from Github.

For CRAN hosted packages in my Description file I can specify something like:

Imports:
    remotes (>= 2.4.0),
    package2,
    etc...

For github maintained packages though I specify through Remotes section:

Remotes: 
    github_username1/repo_name1,
    github_username2/repo_name2,
    etc...

However, when I try specifying either a version number or commit number in that section:

Remotes: 
    github_username1/repo_name1 (>= 0.2.5),
    github_username2/repo_name2

or

Remotes: 
    github_username1/repo_name1 (>= 84jdjk298fkd20jkdj28ddk29dj38dj38dj38),
    github_username2/repo_name2

Then when I try and install my package I get the following error:

Error: Failed to install 'my_package_name' from GitHub:
  Missing commas separating Remotes: 'github_username1/repo_name1 (>= 0.2.5)`

But I have the comma in appropriate place before next package listing. Does Remotes section not support this kind of version specification or does it need to be done different way?

Prefer to have this built in rather than having extra installation instructions for end user to install specific package version with extra install_github command.

Thanks! Sam