Change scheme label in chemmacros

Question

I need to change the labelling for my floats (Page numbers/sections/figures/tables/schemes) into Figure S1, Table S1, Scheme S1, ... (for Supporting Infortmation of a journal).

For Figures and Tables, I found this code, which works perfectly fine:

\renewcommand{\thepage}{S\arabic{page}}  
\renewcommand{\thesection}{S\arabic{section}}   
\renewcommand{\thetable}{S\arabic{table}}   
\renewcommand{\thefigure}{S\arabic{figure}}

However, if I try to do the analogy with the scheme environment from the chemmacros package

\renewcommand{\thescheme}{S\arabic{scheme}} 

I get the following error in the log-file:

Command \thescheme undefined.

I'm not that an expert in code reading, so I did not manage to get the right label description for the scheme environment out of the chemmacros package code. Any suggestions to get this renaming to work is highly appreciated!

Answer 1

OK, after searching few more hours, I found this post, stating that some changes of redefining chemmacros definitions are only affective after \begin{document}.

I don't know the reason for this, but here is what I did and now I get the correct renaming of Scheme 1 towards Scheme S1:

\AtBeginDocument{\renewcommand\thescheme{S\arabic{scheme}}}

Maybe some LATEX gurus can explain this behaviour to me and other newbies? Anyway, I think it is worth to share this solution (workaround?).