diff --git a/src/_brew_cask b/src/_brew_cask
new file mode 100644
index 0000000..e205348
--- /dev/null
+++ b/src/_brew_cask
@@ -0,0 +1,83 @@
+#compdef brew-cask
+#autoload
+
+# Autocompletion for homebrew-cask (https://github.com/caskroom/homebrew-cask/).
+#
+# Originally sourced from the oh-my-zsh
+# https://github.com/robbyrussell/oh-my-zsh/blob/master/plugins/brew-cask/brew-cask.plugin.zsh
+#
+# The MIT License (MIT)
+#
+# Copyright (c) 2009-2016 Robby Russell and contributors
+# See the full list at https://github.com/robbyrussell/oh-my-zsh/contributors
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+
+_brew_cask()
+{
+  local curcontext="$curcontext" state state_descr line
+  typeset -A opt_args
+
+  _arguments -C \
+    ':subcmd:->subcmd' \
+    '*::options:->options'
+
+  case $state in
+  (subcmd)
+    local -a subcommands
+    subcommands=(
+      'audit:verifies installability of Casks'
+      'cat:dump raw source of the given Cask to the standard output'
+      'cleanup:cleans up cached downloads and tracker symlinks'
+      'create:creates the given Cask and opens it in an editor'
+      'doctor:checks for configuration issues'
+      'edit:edits the given Cask'
+      'fetch:downloads remote application files to local cache'
+      'home:opens the homepage of the given Cask'
+      'info:displays information about the given Cask'
+      'install:installs the given Cask'
+      'list:with no args, lists installed Casks; given installed Casks, lists staged files'
+      'search:searches all known Casks'
+      'style:checks Cask style using RuboCop'
+      'uninstall:uninstalls the given Cask'
+      "update:a synonym for 'brew update'"
+      'zap:zaps all files associated with the given Cask'
+    )
+    _describe -t commands "brew cask subcommand" subcommands ;;
+  (options)
+    local -a casks installed_casks
+    local expl
+    case "$line[1]" in
+      list|uninstall)
+        __brew_installed_casks
+        _wanted installed_casks expl 'installed casks' compadd -a installed_casks ;;
+      audit|cat|edit|fetch|home|info|install|zap)
+        __brew_all_casks
+        _wanted casks expl 'all casks' compadd -a casks ;;
+    esac ;;
+  esac
+}
+
+__brew_all_casks() {
+  casks=(`brew cask search`)
+}
+
+__brew_installed_casks() {
+  installed_casks=(`brew cask list|sed 's/(!)//'`)
+}