diff --git a/Casks/thunderbird-beta.rb b/Casks/thunderbird-beta.rb
new file mode 100644
index 000000000..ded21d323
--- /dev/null
+++ b/Casks/thunderbird-beta.rb
@@ -0,0 +1,9 @@
+class ThunderbirdBeta < Cask
+  version '31.0b3'
+  sha256 '82cf13b42f72a660920cfd025220d2ce9ddfb56327b01721b4b02e065752061d'
+
+  url 'https://download-installer.cdn.mozilla.net/pub/thunderbird/releases/31.0b3/mac/en-US/Thunderbird%2031.0b3.dmg'
+  homepage 'https://www.mozilla.org/en-US/thunderbird/all-beta.html'
+
+  link 'Thunderbird.app'
+end