diff --git a/completions/rbenv.fish b/completions/rbenv.fish
deleted file mode 100644
index d347410..0000000
--- a/completions/rbenv.fish
+++ /dev/null
@@ -1,23 +0,0 @@
-function __fish_rbenv_needs_command
-  set cmd (commandline -opc)
-  if [ (count $cmd) -eq 1 -a $cmd[1] = 'rbenv' ]
-    return 0
-  end
-  return 1
-end
-
-function __fish_rbenv_using_command
-  set cmd (commandline -opc)
-  if [ (count $cmd) -gt 1 ]
-    if [ $argv[1] = $cmd[2] ]
-      return 0
-    end
-  end
-  return 1
-end
-
-complete -f -c rbenv -n '__fish_rbenv_needs_command' -a '(rbenv commands)'
-for cmd in (rbenv commands)
-  complete -f -c rbenv -n "__fish_rbenv_using_command $cmd" -a \
-    "(rbenv completions (commandline -opc)[2..-1])"
-end
diff --git a/completions/rbenv.zsh b/completions/rbenv.zsh
new file mode 100644
index 0000000..5b23d42
--- /dev/null
+++ b/completions/rbenv.zsh
@@ -0,0 +1,18 @@
+if [[ ! -o interactive ]]; then
+    return
+fi
+
+compctl -K _rbenv rbenv
+
+_rbenv() {
+  local words completions
+  read -cA words
+
+  if [ "${#words}" -eq 2 ]; then
+    completions="$(rbenv commands)"
+  else
+    completions="$(rbenv completions ${words[2,-2]})"
+  fi
+
+  reply=("${(ps:\n:)completions}")
+}