diff --git a/Library/Homebrew/extend/os/mac/keg_relocate.rb b/Library/Homebrew/extend/os/mac/keg_relocate.rb
index 7a1f42f8b5..707710be61 100644
--- a/Library/Homebrew/extend/os/mac/keg_relocate.rb
+++ b/Library/Homebrew/extend/os/mac/keg_relocate.rb
@@ -2,10 +2,7 @@ class Keg
   def fix_dynamic_linkage
     mach_o_files.each do |file|
       file.ensure_writable do
-        if file.dylib?
-          @require_relocation = true
-          file.change_dylib_id(dylib_id_for(file))
-        end
+        change_dylib_id(dylib_id_for(file), file) if file.dylib?
 
         each_install_name_for(file) do |bad_name|
           # Don't fix absolute paths unless they are rooted in the build directory
@@ -14,9 +11,7 @@ class Keg
                   !bad_name.start_with?(HOMEBREW_TEMP.realpath.to_s)
 
           new_name = fixed_name(file, bad_name)
-
-          @require_relocation = true
-          file.change_install_name(bad_name, new_name, file)
+          change_install_name(bad_name, new_name, file) unless new_name == bad_name
         end
       end
     end
@@ -28,9 +23,8 @@ class Keg
     mach_o_files.each do |file|
       file.ensure_writable do
         if file.dylib?
-          @require_relocation = true
           id = dylib_id_for(file).sub(relocation.old_prefix, relocation.new_prefix)
-          file.change_dylib_id(id)
+          change_dylib_id(id, file)
         end
 
         each_install_name_for(file) do |old_name|
@@ -40,8 +34,7 @@ class Keg
             new_name = old_name.sub(relocation.old_prefix, relocation.new_prefix)
           end
 
-          @require_relocation = true
-          file.change_install_name(old_name, new_name) if new_name
+          change_install_name(old_name, new_name, file) if new_name
         end
       end
     end
diff --git a/Library/Homebrew/os/mac.rb b/Library/Homebrew/os/mac.rb
index e8c92a6074..15c301f994 100644
--- a/Library/Homebrew/os/mac.rb
+++ b/Library/Homebrew/os/mac.rb
@@ -5,6 +5,7 @@ require "os/mac/xcode"
 require "os/mac/xquartz"
 require "os/mac/pathname"
 require "os/mac/sdk"
+require "os/mac/keg"
 
 module OS
   module Mac
diff --git a/Library/Homebrew/os/mac/keg.rb b/Library/Homebrew/os/mac/keg.rb
new file mode 100644
index 0000000000..6caadb1d7a
--- /dev/null
+++ b/Library/Homebrew/os/mac/keg.rb
@@ -0,0 +1,29 @@
+class Keg
+  def change_dylib_id(id, file)
+    return if file.dylib_id == id
+    @require_relocation = true
+    puts "Changing dylib ID of #{file}\n  from #{file.dylib_id}\n    to #{id}" if ARGV.debug?
+    MachO::Tools.change_dylib_id(file, id, strict: false)
+  rescue MachO::MachOError
+    onoe <<-EOS.undent
+      Failed changing dylib ID of #{file}
+        from #{file.dylib_id}
+          to #{id}
+    EOS
+    raise
+  end
+
+  def change_install_name(old, new, file)
+    return if old == new
+    @require_relocation = true
+    puts "Changing install name in #{file}\n  from #{old}\n    to #{new}" if ARGV.debug?
+    MachO::Tools.change_install_name(file, old, new, strict: false)
+  rescue MachO::MachOError
+    onoe <<-EOS.undent
+      Failed changing install name in #{file}
+        from #{old}
+          to #{new}
+    EOS
+    raise
+  end
+end
diff --git a/Library/Homebrew/os/mac/mach.rb b/Library/Homebrew/os/mac/mach.rb
index 29273cbaab..9b53c49797 100644
--- a/Library/Homebrew/os/mac/mach.rb
+++ b/Library/Homebrew/os/mac/mach.rb
@@ -61,34 +61,6 @@ module MachOShim
     macho.dylib_id
   end
 
-  def change_dylib_id(id)
-    return if dylib_id == id
-    puts "Changing dylib ID of #{self}\n  from #{dylib_id}\n    to #{id}" if ARGV.debug?
-    macho.change_dylib_id(id, strict: false)
-    macho.write!
-  rescue MachO::MachOError
-    odie <<-EOS.undent
-      Failed changing dylib ID of #{self}
-        from #{file.dylib_id}
-          to #{id}
-    EOS
-    raise
-  end
-
-  def change_install_name(old, new)
-    return if old == new
-    puts "Changing install name in #{self}\n  from #{old}\n    to #{new}" if ARGV.debug?
-    macho.change_install_name(old, new, strict: false)
-    macho.write!
-  rescue MachO::MachOError
-    odie <<-EOS.undent
-      Failed changing install name in #{self}
-        from #{old}
-          to #{new}
-    EOS
-    raise
-  end
-
   def archs
     mach_data.map { |m| m.fetch :arch }.extend(ArchitectureListExtension)
   end