diff --git a/Library/Homebrew/cmd/tap.rb b/Library/Homebrew/cmd/tap.rb
index 94362f7fe4..6aaf39776b 100644
--- a/Library/Homebrew/cmd/tap.rb
+++ b/Library/Homebrew/cmd/tap.rb
@@ -39,7 +39,7 @@ module Homebrew
     if ARGV.include? "--repair"
       Tap.each(&:link_completions_and_manpages)
     elsif ARGV.include? "--list-official"
-      odeprecated("brew tap --list-official")
+      odisabled("brew tap --list-official")
     elsif ARGV.include? "--list-pinned"
       puts Tap.select(&:pinned?).map(&:name)
     elsif ARGV.named.empty?
diff --git a/Library/Homebrew/cmd/upgrade.rb b/Library/Homebrew/cmd/upgrade.rb
index c6e79ea9f4..c0c989c9fe 100644
--- a/Library/Homebrew/cmd/upgrade.rb
+++ b/Library/Homebrew/cmd/upgrade.rb
@@ -31,8 +31,6 @@ module Homebrew
 
     Install.perform_preinstall_checks
 
-    odisabled "'brew upgrade --all'", "'brew upgrade'" if ARGV.include?("--all")
-
     if ARGV.named.empty?
       outdated = Formula.installed.select do |f|
         f.outdated?(fetch_head: ARGV.fetch_head?)
diff --git a/Library/Homebrew/compat.rb b/Library/Homebrew/compat.rb
index 28630befb9..fbb74cb546 100644
--- a/Library/Homebrew/compat.rb
+++ b/Library/Homebrew/compat.rb
@@ -1,12 +1,7 @@
-require "compat/hbc"
-require "compat/formula"
-require "compat/formula_support"
-require "compat/requirements"
-require "compat/download_strategy"
-require "compat/dependency_collector"
-require "compat/ENV/shared"
-require "compat/extend/string"
-require "compat/gpg"
-require "compat/dependable"
 require "compat/os/mac"
+require "compat/dependable"
+require "compat/dependency_collector"
+require "compat/fileutils"
+require "compat/formula_support"
+require "compat/hbc"
 require "compat/tap"
diff --git a/Library/Homebrew/compat/ENV/shared.rb b/Library/Homebrew/compat/ENV/shared.rb
deleted file mode 100644
index 4e8cd32918..0000000000
--- a/Library/Homebrew/compat/ENV/shared.rb
+++ /dev/null
@@ -1,13 +0,0 @@
-module SharedEnvExtension
-  module Compat
-    def j1
-      odisabled "ENV.j1", "ENV.deparallelize"
-    end
-
-    def java_cache
-      odisabled "ENV.java_cache"
-    end
-  end
-
-  prepend Compat
-end
diff --git a/Library/Homebrew/compat/dependable.rb b/Library/Homebrew/compat/dependable.rb
index 583bf51dab..63195686a5 100644
--- a/Library/Homebrew/compat/dependable.rb
+++ b/Library/Homebrew/compat/dependable.rb
@@ -1,7 +1,7 @@
 module Dependable
   module Compat
     def run?
-      odeprecated "Dependable#run?"
+      odisabled "Dependable#run?"
       tags.include? :run
     end
   end
diff --git a/Library/Homebrew/compat/dependency_collector.rb b/Library/Homebrew/compat/dependency_collector.rb
index 685bbaf0ea..5acfc8f5f5 100644
--- a/Library/Homebrew/compat/dependency_collector.rb
+++ b/Library/Homebrew/compat/dependency_collector.rb
@@ -2,60 +2,10 @@ require "dependency_collector"
 
 class DependencyCollector
   module Compat
-    # Define the languages that we can handle as external dependencies.
-    LANGUAGE_MODULES = Set[
-      :lua, :lua51, :perl, :python, :python3, :ruby
-    ].freeze
-
     def parse_string_spec(spec, tags)
-      if (tag = tags.first) && LANGUAGE_MODULES.include?(tag)
-        odisabled "'depends_on ... => #{tag.inspect}'"
-      end
-
-      if tags.include?(:run)
-        odeprecated "'depends_on ... => :run'"
-      end
-
+      odisabled "'depends_on ... => :run'" if tags.include?(:run)
       super
     end
-
-    def parse_symbol_spec(spec, tags)
-      case spec
-      when :clt
-        odisabled "'depends_on :clt'"
-      when :tex
-        odisabled "'depends_on :tex'"
-      when :libltdl
-        output_disabled(spec, "libtool")
-      when :apr
-        output_disabled(spec, "apr-util")
-      when :fortran
-        output_disabled(spec, "gcc")
-      when :gpg
-        output_disabled(spec, "gnupg")
-      when :hg
-        output_disabled(spec, "mercurial")
-      when :mpi
-        output_disabled(spec, "open-mpi")
-      when :python, :python2
-        output_disabled(spec, "python@2")
-      when :python3
-        output_disabled(spec, "python")
-      when :ant, :autoconf, :automake, :bsdmake, :cairo, :emacs, :expat,
-           :fontconfig, :freetype, :libtool, :libpng, :mysql, :perl, :pixman,
-           :postgresql, :rbenv, :ruby
-        output_disabled(spec)
-      else
-        super
-      end
-    end
-
-    private
-
-    def output_disabled(dependency, new_dependency = dependency)
-      odisabled "'depends_on :#{dependency}'",
-                "'depends_on \"#{new_dependency}\"'"
-    end
   end
 
   prepend Compat
diff --git a/Library/Homebrew/compat/download_strategy.rb b/Library/Homebrew/compat/download_strategy.rb
deleted file mode 100644
index ebc84786b0..0000000000
--- a/Library/Homebrew/compat/download_strategy.rb
+++ /dev/null
@@ -1,6 +0,0 @@
-require "download_strategy"
-
-CurlSSL3DownloadStrategy = CurlDownloadStrategy
-CurlUnsafeDownloadStrategy = CurlDownloadStrategy
-StrictSubversionDownloadStrategy = SubversionDownloadStrategy
-UnsafeSubversionDownloadStrategy = SubversionDownloadStrategy
diff --git a/Library/Homebrew/compat/extend/string.rb b/Library/Homebrew/compat/extend/string.rb
deleted file mode 100644
index 3155168149..0000000000
--- a/Library/Homebrew/compat/extend/string.rb
+++ /dev/null
@@ -1,23 +0,0 @@
-class String
-  module Compat
-    def undent
-      odisabled "<<-EOS.undent", "<<~EOS"
-      self
-    end
-    alias unindent undent
-
-    # eg:
-    #   if foo then <<-EOS.undent_________________________________________________________72
-    #               Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do
-    #               eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad
-    #               minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip
-    #               ex ea commodo consequat. Duis aute irure dolor in reprehenderit in
-    #               voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur
-    #               sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt
-    #               mollit anim id est laborum.
-    #               EOS
-    alias undent_________________________________________________________72 undent
-  end
-
-  prepend Compat
-end
diff --git a/Library/Homebrew/compat/fileutils.rb b/Library/Homebrew/compat/fileutils.rb
index ed7d106f99..0304956aef 100644
--- a/Library/Homebrew/compat/fileutils.rb
+++ b/Library/Homebrew/compat/fileutils.rb
@@ -2,8 +2,13 @@ require "fileutils"
 
 module FileUtils
   module Compat
+    def ruby(*args)
+      odeprecated "ruby", 'system "ruby"'
+      system RUBY_PATH, *args
+    end
+
     def mktemp(prefix = name, opts = {})
-      # odeprecated("FileUtils.mktemp", "mktemp")
+      odeprecated("FileUtils.mktemp", "mktemp")
       Mktemp.new(prefix, opts).run do |staging|
         yield staging
       end
diff --git a/Library/Homebrew/compat/formula.rb b/Library/Homebrew/compat/formula.rb
deleted file mode 100644
index 7432865f12..0000000000
--- a/Library/Homebrew/compat/formula.rb
+++ /dev/null
@@ -1,9 +0,0 @@
-class Formula
-  module Compat
-    def rake(*)
-      odisabled "FileUtils#rake", "system \"rake\""
-    end
-  end
-
-  prepend Compat
-end
diff --git a/Library/Homebrew/compat/formula_support.rb b/Library/Homebrew/compat/formula_support.rb
index 81c37f313d..7cce3a80b2 100644
--- a/Library/Homebrew/compat/formula_support.rb
+++ b/Library/Homebrew/compat/formula_support.rb
@@ -4,27 +4,23 @@ class KegOnlyReason
   module Compat
     def valid?
       case @reason
-      when :provided_by_osx
-        odisabled "keg_only :provided_by_osx", "keg_only :provided_by_macos"
-      when :shadowed_by_osx
-        odisabled "keg_only :shadowed_by_osx", "keg_only :shadowed_by_macos"
       when :provided_pre_mountain_lion
-        odeprecated "keg_only :provided_pre_mountain_lion"
+        odisabled "keg_only :provided_pre_mountain_lion"
         MacOS.version < :mountain_lion
       when :provided_pre_mavericks
-        odeprecated "keg_only :provided_pre_mavericks"
+        odisabled "keg_only :provided_pre_mavericks"
         MacOS.version < :mavericks
       when :provided_pre_el_capitan
-        odeprecated "keg_only :provided_pre_el_capitan"
+        odisabled "keg_only :provided_pre_el_capitan"
         MacOS.version < :el_capitan
       when :provided_pre_high_sierra
-        odeprecated "keg_only :provided_pre_high_sierra"
+        odisabled "keg_only :provided_pre_high_sierra"
         MacOS.version < :high_sierra
       when :provided_until_xcode43
-        odeprecated "keg_only :provided_until_xcode43"
+        odisabled "keg_only :provided_until_xcode43"
         MacOS::Xcode.version < "4.3"
       when :provided_until_xcode5
-        odeprecated "keg_only :provided_until_xcode5"
+        odisabled "keg_only :provided_until_xcode5"
         MacOS::Xcode.version < "5.0"
       else
         super
@@ -33,42 +29,38 @@ class KegOnlyReason
 
     def to_s
       case @reason
-      when :provided_by_osx
-        odisabled "keg_only :provided_by_osx", "keg_only :provided_by_macos"
-      when :shadowed_by_osx
-        odisabled "keg_only :shadowed_by_osx", "keg_only :shadowed_by_macos"
       when :provided_pre_mountain_lion
-        odeprecated "keg_only :provided_pre_mountain_lion"
+        odisabled "keg_only :provided_pre_mountain_lion"
 
         <<~EOS
           macOS already provides this software in versions before Mountain Lion
         EOS
       when :provided_pre_mavericks
-        odeprecated "keg_only :provided_pre_mavericks"
+        odisabled "keg_only :provided_pre_mavericks"
 
         <<~EOS
           macOS already provides this software in versions before Mavericks
         EOS
       when :provided_pre_el_capitan
-        odeprecated "keg_only :provided_pre_el_capitan"
+        odisabled "keg_only :provided_pre_el_capitan"
 
         <<~EOS
           macOS already provides this software in versions before El Capitan
         EOS
       when :provided_pre_high_sierra
-        odeprecated "keg_only :provided_pre_high_sierra"
+        odisabled "keg_only :provided_pre_high_sierra"
 
         <<~EOS
           macOS already provides this software in versions before High Sierra
         EOS
       when :provided_until_xcode43
-        odeprecated "keg_only :provided_until_xcode43"
+        odisabled "keg_only :provided_until_xcode43"
 
         <<~EOS
           Xcode provides this software prior to version 4.3
         EOS
       when :provided_until_xcode5
-        odeprecated "keg_only :provided_until_xcode5"
+        odisabled "keg_only :provided_until_xcode5"
 
         <<~EOS
           Xcode provides this software prior to version 5
diff --git a/Library/Homebrew/compat/gpg.rb b/Library/Homebrew/compat/gpg.rb
deleted file mode 100644
index ef2bec4028..0000000000
--- a/Library/Homebrew/compat/gpg.rb
+++ /dev/null
@@ -1,27 +0,0 @@
-module Gpg
-  class << self
-    module Compat
-      def executable
-        odisabled "Gpg.executable", 'which "gpg"'
-      end
-
-      def available?
-        odisabled "Gpg.available?", 'which "gpg"'
-      end
-
-      def create_test_key(*)
-        odisabled "Gpg.create_test_key"
-      end
-
-      def cleanup_test_processes!
-        odisabled "Gpg.cleanup_test_processes!"
-      end
-
-      def test(*)
-        odisabled "Gpg.test"
-      end
-    end
-
-    prepend Compat
-  end
-end
diff --git a/Library/Homebrew/compat/hbc.rb b/Library/Homebrew/compat/hbc.rb
index e41f39f856..0ebb67e15a 100644
--- a/Library/Homebrew/compat/hbc.rb
+++ b/Library/Homebrew/compat/hbc.rb
@@ -1,9 +1,7 @@
 require "compat/hbc/cask_loader"
 require "compat/hbc/cli/search"
-require "compat/hbc/cli/update"
 require "compat/hbc/cache"
 require "compat/hbc/caskroom"
-require "compat/hbc/cli"
 require "compat/hbc/dsl"
 
 module Hbc
diff --git a/Library/Homebrew/compat/hbc/cask_loader.rb b/Library/Homebrew/compat/hbc/cask_loader.rb
index c62c001a2f..c3e456bf27 100644
--- a/Library/Homebrew/compat/hbc/cask_loader.rb
+++ b/Library/Homebrew/compat/hbc/cask_loader.rb
@@ -8,7 +8,7 @@ module Hbc
 
         def cask(header_token, **options, &block)
           if header_token.is_a?(Hash) && header_token.key?(:v1)
-            odeprecated %q("cask :v1 => 'token'"), %q("cask 'token'")
+            odisabled %q("cask :v1 => 'token'"), %q("cask 'token'")
             header_token = header_token[:v1]
           end
 
diff --git a/Library/Homebrew/compat/hbc/cli.rb b/Library/Homebrew/compat/hbc/cli.rb
deleted file mode 100644
index b80fd409d0..0000000000
--- a/Library/Homebrew/compat/hbc/cli.rb
+++ /dev/null
@@ -1,18 +0,0 @@
-require "hbc/cli/options"
-
-module Hbc
-  class CLI
-    include Options
-
-    option "--binarydir=PATH", (lambda do |*|
-      opoo <<~EOS
-        Option --binarydir is obsolete!
-        Homebrew-Cask now uses the same location as your Homebrew installation for executable links.
-      EOS
-    end)
-
-    option "--caskroom=PATH", (lambda do |*|
-      odisabled "`brew cask` with the `--caskroom` flag"
-    end)
-  end
-end
diff --git a/Library/Homebrew/compat/hbc/cli/update.rb b/Library/Homebrew/compat/hbc/cli/update.rb
deleted file mode 100644
index 5f0f255d86..0000000000
--- a/Library/Homebrew/compat/hbc/cli/update.rb
+++ /dev/null
@@ -1,19 +0,0 @@
-require "hbc/cli/abstract_command"
-
-module Hbc
-  class CLI
-    module Compat
-      class Update < AbstractCommand
-        def run
-          odisabled "`brew cask update`", "`brew update`"
-        end
-
-        def self.visible
-          false
-        end
-      end
-    end
-
-    prepend Compat
-  end
-end
diff --git a/Library/Homebrew/compat/hbc/dsl.rb b/Library/Homebrew/compat/hbc/dsl.rb
index 483ca4a7e6..14cc2b5335 100644
--- a/Library/Homebrew/compat/hbc/dsl.rb
+++ b/Library/Homebrew/compat/hbc/dsl.rb
@@ -2,7 +2,7 @@ module Hbc
   class DSL
     module Compat
       def license(*)
-        odeprecated "Hbc::DSL#license"
+        odisabled "Hbc::DSL#license"
       end
     end
 
diff --git a/Library/Homebrew/compat/os/mac.rb b/Library/Homebrew/compat/os/mac.rb
index a839399c2e..a9389acaff 100644
--- a/Library/Homebrew/compat/os/mac.rb
+++ b/Library/Homebrew/compat/os/mac.rb
@@ -3,7 +3,7 @@ module OS
     class << self
       module Compat
         def release
-          odeprecated "MacOS.release", "MacOS.version"
+          odisabled "MacOS.release", "MacOS.version"
           version
         end
       end
diff --git a/Library/Homebrew/compat/requirements.rb b/Library/Homebrew/compat/requirements.rb
deleted file mode 100644
index af0a9a25d0..0000000000
--- a/Library/Homebrew/compat/requirements.rb
+++ /dev/null
@@ -1,117 +0,0 @@
-require "requirements"
-
-class CVSRequirement < Requirement
-  fatal true
-  satisfy do
-    odisabled("CVSRequirement", "'depends_on \"cvs\"'")
-  end
-end
-
-class EmacsRequirement < Requirement
-  fatal true
-  satisfy do
-    odisabled("EmacsRequirement", "'depends_on \"emacs\"'")
-  end
-end
-
-class FortranRequirement < Requirement
-  fatal true
-  satisfy do
-    odisabled("FortranRequirement", "'depends_on \"gcc\"'")
-  end
-end
-
-class GitRequirement < Requirement
-  fatal true
-  satisfy do
-    odisabled("GitRequirement", "'depends_on \"git\"'")
-  end
-end
-
-class GPG2Requirement < Requirement
-  fatal true
-  satisfy do
-    odisabled("GPG2Requirement", "'depends_on \"gnupg\"'")
-  end
-end
-
-class MercurialRequirement < Requirement
-  fatal true
-  satisfy do
-    odisabled("MercurialRequirement", "'depends_on \"mercurial\"'")
-  end
-end
-
-class MPIRequirement < Requirement
-  fatal true
-  satisfy do
-    odisabled("MPIRequirement", "'depends_on \"open-mpi\"'")
-  end
-end
-
-class MysqlRequirement < Requirement
-  fatal true
-  satisfy do
-    odisabled("MysqlRequirement", "'depends_on \"mysql\"'")
-  end
-end
-
-class PerlRequirement < Requirement
-  fatal true
-  satisfy do
-    odisabled("PerlRequirement", "'depends_on \"perl\"'")
-  end
-end
-
-class PostgresqlRequirement < Requirement
-  fatal true
-  satisfy do
-    odisabled("PostgresqlRequirement", "'depends_on \"postgresql\"'")
-  end
-end
-
-class PythonRequirement < Requirement
-  fatal true
-  satisfy do
-    odisabled("PythonRequirement", "'depends_on \"python@2\"'")
-  end
-end
-
-class Python3Requirement < Requirement
-  fatal true
-  satisfy do
-    odisabled("Python3Requirement", "'depends_on \"python\"'")
-  end
-end
-
-class RbenvRequirement < Requirement
-  fatal true
-  satisfy do
-    odisabled("RbenvRequirement", "'depends_on \"rbenv\"'")
-  end
-end
-
-class RubyRequirement < Requirement
-  fatal true
-  satisfy do
-    odisabled("RubyRequirement", "'depends_on \"ruby\"'")
-  end
-end
-
-class SubversionRequirement < Requirement
-  fatal true
-  satisfy do
-    odisabled("SubversionRequirement", "'depends_on \"subversion\"'")
-  end
-end
-
-class TeXRequirement < Requirement
-  fatal true
-  cask "mactex"
-  download "https://www.tug.org/mactex/"
-  satisfy do
-    odisabled("TeXRequirement")
-  end
-end
-
-MinimumMacOSRequirement = MacOSRequirement
diff --git a/Library/Homebrew/dev-cmd/audit.rb b/Library/Homebrew/dev-cmd/audit.rb
index fc7bf35270..bad484be7a 100644
--- a/Library/Homebrew/dev-cmd/audit.rb
+++ b/Library/Homebrew/dev-cmd/audit.rb
@@ -392,7 +392,7 @@ module Homebrew
 
           if @new_formula && dep_f.keg_only_reason &&
              !["openssl", "apr", "apr-util"].include?(dep.name) &&
-             [:provided_by_macos, :provided_by_osx].include?(dep_f.keg_only_reason.reason)
+             dep_f.keg_only_reason.reason == :provided_by_macos
             new_formula_problem "Dependency '#{dep.name}' may be unnecessary as it is provided by macOS; try to build this formula without it."
           end
 
diff --git a/Library/Homebrew/extend/fileutils.rb b/Library/Homebrew/extend/fileutils.rb
index da65fe4f62..2aa83d50c7 100644
--- a/Library/Homebrew/extend/fileutils.rb
+++ b/Library/Homebrew/extend/fileutils.rb
@@ -43,16 +43,6 @@ module FileUtils
     end
   end
 
-  if method_defined?(:ruby)
-    # @private
-    alias old_ruby ruby
-  end
-
-  # Run the `ruby` Homebrew is using rather than whatever is in the `PATH`.
-  def ruby(*args)
-    system RUBY_PATH, *args
-  end
-
   # Run `xcodebuild` without Homebrew's compiler environment variables set.
   def xcodebuild(*args)
     removed = ENV.remove_cc_etc
diff --git a/Library/Homebrew/extend/pathname.rb b/Library/Homebrew/extend/pathname.rb
index 3f26cc1833..0abea4b874 100644
--- a/Library/Homebrew/extend/pathname.rb
+++ b/Library/Homebrew/extend/pathname.rb
@@ -134,10 +134,8 @@ class Pathname
   end
   private :install_symlink_p
 
-  if method_defined?(:write)
-    # @private
-    alias old_write write
-  end
+  # @private
+  alias old_write write
 
   # we assume this pathname object is a file obviously
   def write(content, *open_args)
@@ -152,18 +150,6 @@ class Pathname
     open("a", *open_args) { |f| f.puts(content) }
   end
 
-  unless method_defined?(:binwrite)
-    def binwrite(contents, *open_args)
-      open("wb", *open_args) { |f| f.write(contents) }
-    end
-  end
-
-  unless method_defined?(:binread)
-    def binread(*open_args)
-      open("rb", *open_args, &:read)
-    end
-  end
-
   # NOTE always overwrites
   def atomic_write(content)
     require "tempfile"
@@ -279,7 +265,7 @@ class Pathname
     raise ChecksumMismatchError.new(self, expected, actual) unless expected == actual
   end
 
-  alias to_str to_s unless method_defined?(:to_str)
+  alias to_str to_s
 
   def cd
     Dir.chdir(self) { yield self }
@@ -310,15 +296,6 @@ class Pathname
     File.symlink(src.relative_path_from(dirname), self)
   end
 
-  unless method_defined?(:/)
-    def /(other)
-      if !other.respond_to?(:to_str) && !other.respond_to?(:to_path)
-        odisabled "Pathname#/ with #{other.class}", "a String or a Pathname"
-      end
-      join(other.to_s)
-    end
-  end
-
   # @private
   def ensure_writable
     saved_perms = nil
diff --git a/Library/Homebrew/formulary.rb b/Library/Homebrew/formulary.rb
index 886f739d69..d5a0baeba6 100644
--- a/Library/Homebrew/formulary.rb
+++ b/Library/Homebrew/formulary.rb
@@ -47,14 +47,8 @@ module Formulary
     cache[path] = klass
   end
 
-  if IO.method_defined?(:set_encoding)
-    def self.ensure_utf8_encoding(io)
-      io.set_encoding(Encoding::UTF_8)
-    end
-  else
-    def self.ensure_utf8_encoding(io)
-      io
-    end
+  def self.ensure_utf8_encoding(io)
+    io.set_encoding(Encoding::UTF_8)
   end
 
   def self.class_s(name)
diff --git a/Library/Homebrew/test/cask/dsl_spec.rb b/Library/Homebrew/test/cask/dsl_spec.rb
index 6ce40502a6..21684bf2c9 100644
--- a/Library/Homebrew/test/cask/dsl_spec.rb
+++ b/Library/Homebrew/test/cask/dsl_spec.rb
@@ -70,20 +70,6 @@ describe Hbc::DSL, :cask do
         expect(cask.version.to_s).to eq("1.2.3")
       end
     end
-
-    context "when it contains a deprecated DSL version", :needs_compat do
-      let(:token) { "compat/with-dsl-version" }
-
-      it "may use deprecated DSL version hash syntax" do
-        allow(ENV).to receive(:[]).with("HOMEBREW_DEVELOPER").and_return(nil)
-        allow(ENV).to receive(:[]).with("HOMEBREW_NO_COLOR").and_return(nil)
-
-        expect(cask.token).to eq("with-dsl-version")
-        expect(cask.url.to_s).to eq("http://example.com/TestCask.dmg")
-        expect(cask.homepage).to eq("http://example.com/")
-        expect(cask.version.to_s).to eq("1.2.3")
-      end
-    end
   end
 
   describe "name stanza" do
diff --git a/Library/Homebrew/test/dependency_collector_spec.rb b/Library/Homebrew/test/dependency_collector_spec.rb
index 7c37ba706a..c152997c88 100644
--- a/Library/Homebrew/test/dependency_collector_spec.rb
+++ b/Library/Homebrew/test/dependency_collector_spec.rb
@@ -128,15 +128,5 @@ describe DependencyCollector do
       resource.download_strategy = Class.new
       expect { subject.add(resource) }.to raise_error(TypeError)
     end
-
-    it "is deprecated when called with a language module", :needs_compat do
-      expect(subject).to receive(:odeprecated)
-      subject.add("lpeg" => :lua)
-    end
-
-    it "is deprecated when called with deprecated requirements", :needs_compat do
-      expect(subject).to receive(:odeprecated)
-      subject.add(:python)
-    end
   end
 end
diff --git a/Library/Homebrew/test/formula_support_spec.rb b/Library/Homebrew/test/formula_support_spec.rb
index f73d97cece..31fc879d89 100644
--- a/Library/Homebrew/test/formula_support_spec.rb
+++ b/Library/Homebrew/test/formula_support_spec.rb
@@ -11,12 +11,6 @@ describe KegOnlyReason do
       r = described_class.new :provided_by_macos, ""
       expect(r.to_s).to match(/^macOS already provides/)
     end
-
-    it "is deprecated when reason mentions 'osx'", :needs_compat do
-      r = described_class.new :provided_by_osx, "test"
-      expect(r).to receive(:odeprecated)
-      r.to_s
-    end
   end
 end
 
diff --git a/Library/Homebrew/test/mpi_requirement_spec.rb b/Library/Homebrew/test/mpi_requirement_spec.rb
deleted file mode 100644
index d88156e520..0000000000
--- a/Library/Homebrew/test/mpi_requirement_spec.rb
+++ /dev/null
@@ -1,14 +0,0 @@
-require "compat/requirements"
-
-describe MPIRequirement, :needs_compat do
-  describe "::new" do
-    subject { described_class.new(wrappers + tags) }
-
-    let(:wrappers) { [:cc, :cxx, :f77] }
-    let(:tags) { [:optional, "some-other-tag"] }
-
-    it "stores wrappers as tags" do
-      expect(subject.tags).to eq(wrappers + tags)
-    end
-  end
-end