How can I exclude node_modules from Compare wWith?

I have already set the node_modules folder in PhpStorm to be excluded, but when I attempt to compare the project with another project using Compare With... it insists on comparing all the files in the node_modules folder/sub-folders in each project. This makes the comparison take an unnecessarily long time. How can I tell Compare With... to ignore the node_modules folders when performing a comparison?

Thanks!