diff --git a/Library/Homebrew/cmd/update.rb b/Library/Homebrew/cmd/update.rb
index 1186f0e1b7..17dbf3a190 100644
--- a/Library/Homebrew/cmd/update.rb
+++ b/Library/Homebrew/cmd/update.rb
@@ -1,5 +1,7 @@
 require "cmd/tap"
 require "formula_versions"
+require "migrator"
+require "formulary"
 
 module Homebrew
   def update
@@ -46,13 +48,47 @@ module Homebrew
 
     # automatically tap any migrated formulae's new tap
     report.select_formula(:D).each do |f|
-      next unless (HOMEBREW_CELLAR/f).exist?
+      next unless (dir = HOMEBREW_CELLAR/f).exist?
       migration = TAP_MIGRATIONS[f]
       next unless migration
       tap_user, tap_repo = migration.split "/"
       install_tap tap_user, tap_repo
+      # update tap for each Tab
+      tabs = dir.subdirs.each.map { |d| Tab.for_keg(Keg.new(d)) }
+      tabs.each { |tab| tab.source["tap"] = "#{tap_user}/homebrew-#{tap_repo}" }
+      tabs.each(&:write)
     end if load_tap_migrations
 
+    # Migrate installed renamed formulae from main Homebrew repository.
+    if load_formula_renames
+      report.select_formula(:D).each do |oldname|
+        newname = FORMULA_RENAMES[oldname]
+        next unless newname
+        next unless (dir = HOMEBREW_CELLAR/oldname).directory? && !dir.subdirs.empty?
+
+        begin
+          migrator = Migrator.new(Formulary.factory("homebrew/homebrew/#{newname}"))
+          migrator.migrate
+        rescue Migrator::MigratorDifferentTapsError
+        end
+      end
+    end
+
+    # Migrate installed renamed formulae from taps
+    report.select_formula(:D).each do |oldname|
+      user, repo, oldname = oldname.split("/", 3)
+      next unless user && repo && oldname
+      tap = Tap.new(user, repo)
+      next unless newname = tap.formula_renames[oldname]
+      next unless (dir = HOMEBREW_CELLAR/oldname).directory? && !dir.subdirs.empty?
+
+      begin
+        migrator = Migrator.new(Formulary.factory("#{user}/#{repo}/#{newname}"))
+        migrator.migrate
+      rescue Migrator::MigratorDifferentTapsError
+      end
+    end
+
     if report.empty?
       puts "Already up-to-date."
     else
@@ -112,7 +148,13 @@ module Homebrew
   end
 
   def load_tap_migrations
-    require "tap_migrations"
+    load "tap_migrations"
+  rescue LoadError
+    false
+  end
+
+  def load_formula_renames
+    load "formula_renames.rb"
   rescue LoadError
     false
   end