diff --git a/COMMANDS.md b/COMMANDS.md
index eafcd668..6da9c0e4 100644
--- a/COMMANDS.md
+++ b/COMMANDS.md
@@ -267,6 +267,8 @@ you run the given command.
     $ pyenv which python3.3
     /home/yyuu/.pyenv/versions/3.3.3/bin/python3.3
 
+Use --nosystem argument in case when you don't need to search command in the 
+system environment.
 
 ## `pyenv whence`