diff --git a/Library/Homebrew/tab.rb b/Library/Homebrew/tab.rb
index 6e98bb652c..4fad2411df 100644
--- a/Library/Homebrew/tab.rb
+++ b/Library/Homebrew/tab.rb
@@ -126,7 +126,7 @@ class Tab < OpenStruct
       "source" => {
         "path" => nil,
         "tap" => nil,
-        "spec" => nil,
+        "spec" => "stable",
       },
     }