[NTG-context] \installprettytype problem

Hello, I want to use the " C-Pretty-Printing http://modules.contextgarden.net/pret-c" module. According to the "Verbatim" page of the Context garden, I have to use the \installprettytype command, but this one doesn't work (error : "undefined control sequence"). I'm using the 2015.08.13 19:33 Context version. Example : \installprettytype[C][C] \definetyping[C][option=C] \startC int func(int a){ if(a > 4) return 0; // comment else /* comment */ return 10; } \stopC Thank you.