diff --git a/Library/Homebrew/extend/ARGV.rb b/Library/Homebrew/extend/ARGV.rb
index 8f783aea1a..f37c550c88 100644
--- a/Library/Homebrew/extend/ARGV.rb
+++ b/Library/Homebrew/extend/ARGV.rb
@@ -27,9 +27,11 @@ module HomebrewArgvExtension
     @resolved_formulae ||= (downcased_unique_named - casks).map do |name|
       if name.include?("/")
         f = Formulary.factory(name, spec)
-        if spec(default=nil).nil? && f.any_version_installed?
-          installed_spec = Tab.for_formula(f).spec
-          f.set_active_spec(installed_spec) if f.send(installed_spec)
+        if f.any_version_installed?
+          tab = Tab.for_formula(f)
+          resolved_spec = spec(default=nil) || tab.spec
+          f.set_active_spec(resolved_spec) if f.send(resolved_spec)
+          f.build = tab
         end
         f
       else
diff --git a/Library/Homebrew/formulary.rb b/Library/Homebrew/formulary.rb
index 38f71c85a5..c53262db93 100644
--- a/Library/Homebrew/formulary.rb
+++ b/Library/Homebrew/formulary.rb
@@ -227,7 +227,7 @@ class Formulary
     tap = tab.tap
     spec ||= tab.spec
 
-    if tap.nil?
+    f = if tap.nil?
       factory(rack.basename.to_s, spec)
     else
       begin
@@ -237,6 +237,8 @@ class Formulary
         factory(rack.basename.to_s, spec)
       end
     end
+    f.build = tab
+    f
   end
 
   # Return a Formula instance directly from contents