webshot for untrusted https websites

[egarpor]

I have failed on trying to take a webshot of an https site with an untrusted certificate. Here is a MWE:

webshot("https://untrusted-root.badssl.com/")
# Could not load  https://untrusted-root.badssl.com/
# Error in webshot("https://untrusted-root.badssl.com/")

Is this behaviour expected? Is there any alternative for taking screenshots of such sites?

I am using:

> version
               _                           
platform       x86_64-apple-darwin13.4.0   
arch           x86_64                      
os             darwin13.4.0                
system         x86_64, darwin13.4.0        
status                                     
major          3                           
minor          2.3                         
year           2015                        
month          12                          
day            10                          
svn rev        69752                       
language       R                           
version.string R version 3.2.3 (2015-12-10)
nickname       Wooden Christmas-Tree       
> packageVersion("webshot")
[1] ‘0.4.1.9000’