diff --git a/functions b/functions
index 7175021..586dfc7 100644
--- a/functions
+++ b/functions
@@ -55,3 +55,20 @@ function run {
 function npm-exec {
   (PATH=$(npm bin):$PATH; eval $@;)
 }
+
+# lazy loading
+function rbenv {
+  eval "$(command rbenv init -)"
+  rbenv "$@"
+}
+
+function nodeenv {
+  eval "$(command nodenv init -)"
+  nodenv "$@"
+}
+
+function pyenv {
+  eval "$(command pyenv init -)"
+  eval "$(command pyenv virtualenv-init -)"
+  pyenv "$@"
+}
diff --git a/zshrc b/zshrc
index c8896d6..f41015d 100644
--- a/zshrc
+++ b/zshrc
@@ -27,16 +27,6 @@ fi
 zle -N insert-sudo
 bindkey "^z" insert-sudo
 
-# init rbenv
-if test -d "$HOME/.rbenv"; then
-  eval "$(rbenv init -)"
-fi
-
-# init nodenv
-if which nodenv > /dev/null; then
-  eval "$(nodenv init -)";
-fi
-
 # completion
 autoload -U compinit
 compinit