diff --git a/Library/Homebrew/patch.rb b/Library/Homebrew/patch.rb
index 72deabefd9..4b41d972d7 100644
--- a/Library/Homebrew/patch.rb
+++ b/Library/Homebrew/patch.rb
@@ -161,7 +161,7 @@ end
 class LegacyPatch < ExternalPatch
   def initialize(strip, url)
     super(strip)
-    resource.url = url
+    resource.url(url)
     resource.download_strategy = CurlDownloadStrategy
   end
 
diff --git a/Library/Homebrew/resource.rb b/Library/Homebrew/resource.rb
index 550658aa9d..dd7245b4cc 100644
--- a/Library/Homebrew/resource.rb
+++ b/Library/Homebrew/resource.rb
@@ -9,7 +9,7 @@ class Resource
   include FileUtils
 
   attr_reader :checksum, :mirrors, :specs, :using
-  attr_writer :url, :checksum, :version
+  attr_writer :checksum, :version
   attr_accessor :download_strategy
 
   # Formula name must be set after the DSL, as we have no access to the
diff --git a/Library/Homebrew/software_spec.rb b/Library/Homebrew/software_spec.rb
index 1102a4fc3c..a1fba5661a 100644
--- a/Library/Homebrew/software_spec.rb
+++ b/Library/Homebrew/software_spec.rb
@@ -224,7 +224,7 @@ class Bottle
     checksum, tag = spec.checksum_for(bottle_tag)
 
     filename = Filename.create(formula, tag, spec.revision)
-    @resource.url = build_url(spec.root_url, filename)
+    @resource.url(build_url(spec.root_url, filename))
     @resource.download_strategy = CurlBottleDownloadStrategy
     @resource.version = formula.pkg_version
     @resource.checksum = checksum