diff --git a/templates/default/chruby.sh.erb b/templates/default/chruby.sh.erb
index b71cd55..667a020 100644
--- a/templates/default/chruby.sh.erb
+++ b/templates/default/chruby.sh.erb
@@ -1,3 +1,5 @@
+[ -n "$BASH_VERSION" ] || [ -n "$ZSH_VERSION" ] || return
+
 source /usr/local/chruby/share/chruby/chruby.sh
 
 <% if ::File.exists?("/opt/chef/embedded") -%>