diff --git a/Library/Homebrew/cmd/install.rb b/Library/Homebrew/cmd/install.rb
index 935865bcce..d460452c5f 100644
--- a/Library/Homebrew/cmd/install.rb
+++ b/Library/Homebrew/cmd/install.rb
@@ -61,6 +61,7 @@ require "cmd/search"
 require "formula_installer"
 require "tap"
 require "hardware"
+require "development_tools"
 
 module Homebrew
   def install
diff --git a/Library/Homebrew/cmd/reinstall.rb b/Library/Homebrew/cmd/reinstall.rb
index aa705cff3f..a7bbef32da 100644
--- a/Library/Homebrew/cmd/reinstall.rb
+++ b/Library/Homebrew/cmd/reinstall.rb
@@ -2,6 +2,7 @@
 #:    Uninstall then install <formula>
 
 require "formula_installer"
+require "development_tools"
 
 module Homebrew
   def reinstall
diff --git a/Library/Homebrew/cmd/upgrade.rb b/Library/Homebrew/cmd/upgrade.rb
index d2e251783b..382ff6b717 100644
--- a/Library/Homebrew/cmd/upgrade.rb
+++ b/Library/Homebrew/cmd/upgrade.rb
@@ -10,6 +10,7 @@
 
 require "cmd/install"
 require "cleanup"
+require "development_tools"
 
 module Homebrew
   def upgrade
diff --git a/Library/Homebrew/dev-cmd/test-bot.rb b/Library/Homebrew/dev-cmd/test-bot.rb
index 5c4d7000e3..52e73565fc 100644
--- a/Library/Homebrew/dev-cmd/test-bot.rb
+++ b/Library/Homebrew/dev-cmd/test-bot.rb
@@ -39,6 +39,7 @@ require "rexml/document"
 require "rexml/xmldecl"
 require "rexml/cdata"
 require "tap"
+require "development_tools"
 
 module Homebrew
   BYTES_IN_1_MEGABYTE = 1024*1024
diff --git a/Library/Homebrew/diagnostic.rb b/Library/Homebrew/diagnostic.rb
index 62f63b34f0..ccd159989f 100644
--- a/Library/Homebrew/diagnostic.rb
+++ b/Library/Homebrew/diagnostic.rb
@@ -2,6 +2,7 @@ require "keg"
 require "language/python"
 require "formula"
 require "version"
+require "development_tools"
 
 module Homebrew
   module Diagnostic
diff --git a/Library/Homebrew/extend/ENV/shared.rb b/Library/Homebrew/extend/ENV/shared.rb
index 62aa311ec3..3566a5c507 100644
--- a/Library/Homebrew/extend/ENV/shared.rb
+++ b/Library/Homebrew/extend/ENV/shared.rb
@@ -1,5 +1,6 @@
 require "formula"
 require "compilers"
+require "development_tools"
 
 # Homebrew extends Ruby's `ENV` to make our code more readable.
 # Implemented in {SharedEnvExtension} and either {Superenv} or
diff --git a/Library/Homebrew/formula_installer.rb b/Library/Homebrew/formula_installer.rb
index 1285db794f..eb98d80632 100644
--- a/Library/Homebrew/formula_installer.rb
+++ b/Library/Homebrew/formula_installer.rb
@@ -14,6 +14,7 @@ require "debrew"
 require "sandbox"
 require "requirements/cctools_requirement"
 require "emoji"
+require "development_tools"
 
 class FormulaInstaller
   include FormulaCellarChecks
diff --git a/Library/Homebrew/tab.rb b/Library/Homebrew/tab.rb
index 42d4e3645c..22489c4e58 100644
--- a/Library/Homebrew/tab.rb
+++ b/Library/Homebrew/tab.rb
@@ -2,6 +2,7 @@ require "cxxstdlib"
 require "ostruct"
 require "options"
 require "utils/json"
+require "development_tools"
 
 # Inherit from OpenStruct to gain a generic initialization method that takes a
 # hash and creates an attribute for each key and value. `Tab.new` probably