diff --git a/Homebrew/mas.rb b/Homebrew/mas.rb
index 08383dc48..986f28035 100644
--- a/Homebrew/mas.rb
+++ b/Homebrew/mas.rb
@@ -19,6 +19,8 @@ def install
                "-configuration", "Release",
                "SYMROOT=build"
     bin.install "build/mas"
+
+    bash_completion.install "contrib/completion/mas-completion.bash" => "mas"
   end
 
   test do
diff --git a/contrib/completion/mas-completion.bash b/contrib/completion/mas-completion.bash
new file mode 100644
index 000000000..64750e506
--- /dev/null
+++ b/contrib/completion/mas-completion.bash
@@ -0,0 +1,18 @@
+#!/usr/bin/env bash
+
+_mas()
+{
+    local cur prev words cword;
+    if declare -F _init_completions >/dev/null 2>&1; then
+        _init_completion
+    else
+        COMPREPLY=()
+        _get_comp_words_by_ref cur prev words cword
+    fi
+    if [[ $cword -eq 1 ]]; then
+        COMPREPLY=($( compgen -W "$(mas help | tail +3 | awk '{print $1}')" -- "$cur" ));
+        return 0
+    fi
+}
+
+complete -F _mas mas