diff --git a/Library/Homebrew/extend/fileutils.rb b/Library/Homebrew/extend/fileutils.rb
deleted file mode 100644
index 2aa83d50c7..0000000000
--- a/Library/Homebrew/extend/fileutils.rb
+++ /dev/null
@@ -1,53 +0,0 @@
-require "fileutils"
-require "etc"
-
-# Homebrew extends Ruby's `FileUtils` to make our code more readable.
-# @see https://ruby-doc.org/stdlib-2.0.0/libdoc/fileutils/rdoc/FileUtils.html Ruby's FileUtils API
-module FileUtils
-  # @private
-  alias old_mkdir mkdir
-
-  # A version of mkdir that also changes to that folder in a block.
-  def mkdir(name, mode: nil, noop: nil, verbose: nil, &_block)
-    result = mkdir_p(name, mode: mode, noop: noop, verbose: verbose)
-    return result unless block_given?
-    chdir name do
-      yield
-    end
-  end
-  module_function :mkdir
-
-  # Run `scons` using a Homebrew-installed version rather than whatever is in the `PATH`.
-  def scons(*args)
-    system Formulary.factory("scons").opt_bin/"scons", *args
-  end
-
-  # Run `make` 3.81 or newer.
-  # Uses the system make on Leopard and newer, and the
-  # path to the actually-installed make on Tiger or older.
-  def make(*args)
-    if Utils.popen_read("/usr/bin/make", "--version").match(/Make (\d\.\d+)/)[1] > "3.80"
-      make_path = "/usr/bin/make"
-    else
-      make = Formula["make"].opt_bin/"make"
-      make_path = make.exist? ? make.to_s : (Formula["make"].opt_bin/"gmake").to_s
-    end
-
-    if superenv?
-      make_name = File.basename(make_path)
-      with_env(HOMEBREW_MAKE: make_name) do
-        system "make", *args
-      end
-    else
-      system make_path, *args
-    end
-  end
-
-  # Run `xcodebuild` without Homebrew's compiler environment variables set.
-  def xcodebuild(*args)
-    removed = ENV.remove_cc_etc
-    system "xcodebuild", *args
-  ensure
-    ENV.update(removed)
-  end
-end
diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index a58b56a176..f0203cad93 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -1907,6 +1907,56 @@ class Formula
     end
   end
 
+  # A version of `FileUtils.mkdir` that also changes to that folder in
+  # a block.
+  def mkdir(name)
+    result = FileUtils.mkdir_p(name)
+    return result unless block_given?
+    FileUtils.chdir name do
+      yield
+    end
+  end
+
+  # Run `scons` using a Homebrew-installed version rather than whatever is
+  # in the `PATH`.
+  def scons(*args)
+    system Formulary.factory("scons").opt_bin/"scons", *args
+  end
+
+  # Run `make` 3.81 or newer.
+  # Uses the system make on Leopard and newer, and the
+  # path to the actually-installed make on Tiger or older.
+  def make(*args)
+    if Utils.popen_read("/usr/bin/make", "--version")
+            .match(/Make (\d\.\d+)/)[1] > "3.80"
+      make_path = "/usr/bin/make"
+    else
+      make = Formula["make"].opt_bin/"make"
+      make_path = if make.exist?
+        make.to_s
+      else
+        (Formula["make"].opt_bin/"gmake").to_s
+      end
+    end
+
+    if superenv?
+      make_name = File.basename(make_path)
+      with_env(HOMEBREW_MAKE: make_name) do
+        system "make", *args
+      end
+    else
+      system make_path, *args
+    end
+  end
+
+  # Run `xcodebuild` without Homebrew's compiler environment variables set.
+  def xcodebuild(*args)
+    removed = ENV.remove_cc_etc
+    system "xcodebuild", *args
+  ensure
+    ENV.update(removed)
+  end
+
   private
 
   # Returns the prefix for a given formula version number.
diff --git a/Library/Homebrew/global.rb b/Library/Homebrew/global.rb
index 9f7661c719..a28779547e 100644
--- a/Library/Homebrew/global.rb
+++ b/Library/Homebrew/global.rb
@@ -33,7 +33,7 @@ HOMEBREW_BOTTLE_DEFAULT_DOMAIN = ENV["HOMEBREW_BOTTLE_DEFAULT_DOMAIN"] ||
 HOMEBREW_BOTTLE_DOMAIN = ENV["HOMEBREW_BOTTLE_DOMAIN"] ||
                          HOMEBREW_BOTTLE_DEFAULT_DOMAIN
 
-require "extend/fileutils"
+require "fileutils"
 
 module Homebrew
   extend FileUtils
diff --git a/Library/Homebrew/resource.rb b/Library/Homebrew/resource.rb
index 0b2897bd43..e86f48ac1d 100644
--- a/Library/Homebrew/resource.rb
+++ b/Library/Homebrew/resource.rb
@@ -182,6 +182,14 @@ class Resource
     patches << p
   end
 
+  protected
+
+  def mktemp(prefix)
+    Mktemp.new(prefix).run do |staging|
+      yield staging
+    end
+  end
+
   private
 
   def detect_version(val)
@@ -196,12 +204,6 @@ class Resource
     end
   end
 
-  def mktemp(prefix)
-    Mktemp.new(prefix).run do |staging|
-      yield staging
-    end
-  end
-
   class Go < Resource
     def stage(target)
       super(target/name)
diff --git a/Library/Homebrew/test/formula_spec.rb b/Library/Homebrew/test/formula_spec.rb
index 8943e8d325..4ff0851154 100644
--- a/Library/Homebrew/test/formula_spec.rb
+++ b/Library/Homebrew/test/formula_spec.rb
@@ -1303,6 +1303,17 @@ describe Formula do
       end
     end
 
+    describe "#mkdir" do
+      let(:dst) { mktmpdir }
+
+      it "creates intermediate directories" do
+        f.mkdir dst/"foo/bar/baz" do
+          expect(dst/"foo/bar/baz").to exist, "foo/bar/baz was not created"
+          expect(dst/"foo/bar/baz").to be_a_directory, "foo/bar/baz was not a directory structure"
+        end
+      end
+    end
+
     describe "with changed version scheme" do
       let(:f) do
         formula "testball" do
diff --git a/Library/Homebrew/test/pathname_spec.rb b/Library/Homebrew/test/pathname_spec.rb
index 090897f6a3..ca9c846efd 100644
--- a/Library/Homebrew/test/pathname_spec.rb
+++ b/Library/Homebrew/test/pathname_spec.rb
@@ -289,16 +289,3 @@ describe Pathname do
     end
   end
 end
-
-describe FileUtils do
-  let(:dst) { mktmpdir }
-
-  describe "#mkdir" do
-    it "creates intermediate directories" do
-      described_class.mkdir dst/"foo/bar/baz" do
-        expect(dst/"foo/bar/baz").to exist, "foo/bar/baz was not created"
-        expect(dst/"foo/bar/baz").to be_a_directory, "foo/bar/baz was not a directory structure"
-      end
-    end
-  end
-end