diff --git a/Library/Homebrew/resource.rb b/Library/Homebrew/resource.rb
index 6ee5a77214..1170f2b4b3 100644
--- a/Library/Homebrew/resource.rb
+++ b/Library/Homebrew/resource.rb
@@ -183,7 +183,7 @@ class Resource
   #   regex /foo-(\d+(?:\.\d+)+)\.tar/
   # end</pre>
   def livecheck(&block)
-    @livecheck ||= Livecheck.new(self)
+    @livecheck ||= Livecheck.new(self) if block
     return @livecheck unless block
 
     @livecheckable = true