diff --git a/Library/Homebrew/cli/args.rb b/Library/Homebrew/cli/args.rb
index 522b2e550c..2a7b81517e 100644
--- a/Library/Homebrew/cli/args.rb
+++ b/Library/Homebrew/cli/args.rb
@@ -28,14 +28,6 @@ module Homebrew
             .map(&method(:to_cli_option))
             .select { |arg| arg.start_with?("-") }
       end
-
-      def flags_only
-        to_h.keys
-            .map(&:to_s)
-            .reject { |name| %w[argv remaining].include?(name) }
-            .map(&method(:to_cli_option))
-            .select { |arg| arg.start_with?("--") }
-      end
     end
   end
 end
diff --git a/Library/Homebrew/cmd/upgrade.rb b/Library/Homebrew/cmd/upgrade.rb
index 3a3e78e3c4..7ebd0b477e 100644
--- a/Library/Homebrew/cmd/upgrade.rb
+++ b/Library/Homebrew/cmd/upgrade.rb
@@ -162,7 +162,7 @@ module Homebrew
       tab = Tab.for_keg(keg)
     end
 
-    build_options = BuildOptions.new(Options.create(Homebrew.args.flags_only), f.options)
+    build_options = BuildOptions.new(Options.create(ARGV.flags_only), f.options)
     options = build_options.used_options
     options |= f.build.used_options
     options &= f.options
diff --git a/Library/Homebrew/reinstall.rb b/Library/Homebrew/reinstall.rb
index 067d8b38e8..51862302a1 100644
--- a/Library/Homebrew/reinstall.rb
+++ b/Library/Homebrew/reinstall.rb
@@ -16,7 +16,7 @@ module Homebrew
       backup keg
     end
 
-    build_options = BuildOptions.new(Options.create(Homebrew.args.flags_only), f.options)
+    build_options = BuildOptions.new(Options.create(ARGV.flags_only), f.options)
     options = build_options.used_options
     options |= f.build.used_options
     options &= f.options
diff --git a/Library/Homebrew/test/cli/parser_spec.rb b/Library/Homebrew/test/cli/parser_spec.rb
index 9e27eca43e..4fd34553bb 100644
--- a/Library/Homebrew/test/cli/parser_spec.rb
+++ b/Library/Homebrew/test/cli/parser_spec.rb
@@ -225,10 +225,5 @@ describe Homebrew::CLI::Parser do
       parser.parse(["--foo", "-vds", "a", "b", "cdefg"])
       expect(Homebrew.args.options_only).to eq %w[--foo -v -d -s]
     end
-
-    it "#flags_only" do
-      parser.parse(["--foo", "-vds", "a", "b", "cdefg"])
-      expect(Homebrew.args.flags_only).to eq %w[--foo]
-    end
   end
 end