diff --git a/Library/Homebrew/cmd/untap.rb b/Library/Homebrew/cmd/untap.rb
index 3847bf8e35..b734ae04e8 100644
--- a/Library/Homebrew/cmd/untap.rb
+++ b/Library/Homebrew/cmd/untap.rb
@@ -1,7 +1,8 @@
-# typed: true
+# typed: strict
 # frozen_string_literal: true
 
 require "cli/parser"
+require "untap"
 
 module Homebrew
   sig { returns(CLI::Parser) }
@@ -25,8 +26,8 @@ module Homebrew
       odie "Untapping #{tap} is not allowed" if tap.core_tap? && Homebrew::EnvConfig.no_install_from_api?
 
       if Homebrew::EnvConfig.no_install_from_api? || (!tap.core_tap? && !tap.core_cask_tap?)
-        installed_tap_formulae = installed_formulae_for(tap: tap)
-        installed_tap_casks = installed_casks_for(tap: tap)
+        installed_tap_formulae = Untap.installed_formulae_for(tap:)
+        installed_tap_casks = Untap.installed_casks_for(tap:)
 
         if installed_tap_formulae.present? || installed_tap_casks.present?
           installed_names = (installed_tap_formulae + installed_tap_casks.map(&:token)).join("\n")
@@ -47,48 +48,4 @@ module Homebrew
       tap.uninstall manual: true
     end
   end
-
-  sig { params(tap: Tap).returns(T::Array[Formula]) }
-  def self.installed_formulae_for(tap:)
-    tap.formula_names.filter_map do |formula_name|
-      next unless installed_formulae_names.include?(T.must(formula_name.split("/").last))
-
-      formula = begin
-        Formulary.factory(formula_name)
-      rescue
-        # Don't blow up because of a single unavailable formula.
-        next
-      end
-
-      # Can't use Formula#any_version_installed? because it doesn't consider
-      # taps correctly.
-      formula if formula.installed_kegs.any? { |keg| keg.tab.tap == tap }
-    end
-  end
-
-  sig { returns(T::Set[String]) }
-  def self.installed_formulae_names
-    @installed_formulae_names ||= Formula.installed_formula_names.to_set
-  end
-
-  sig { params(tap: Tap).returns(T::Array[Cask::Cask]) }
-  def self.installed_casks_for(tap:)
-    tap.cask_tokens.filter_map do |cask_token|
-      next unless installed_cask_tokens.include?(T.must(cask_token.split("/").last))
-
-      cask = begin
-        Cask::CaskLoader.load(cask_token)
-      rescue
-        # Don't blow up because of a single unavailable cask.
-        next
-      end
-
-      cask if cask.installed?
-    end
-  end
-
-  sig { returns(T::Set[String]) }
-  def self.installed_cask_tokens
-    @installed_cask_tokens ||= Cask::Caskroom.tokens.to_set
-  end
 end
diff --git a/Library/Homebrew/untap.rb b/Library/Homebrew/untap.rb
new file mode 100644
index 0000000000..f32ef0ba4d
--- /dev/null
+++ b/Library/Homebrew/untap.rb
@@ -0,0 +1,56 @@
+# typed: true
+# frozen_string_literal: true
+
+module Homebrew
+  # Helpers for the `brew untap` command.
+  # @api private
+  module Untap
+    # All installed formulae currently available in a tap by formula full name.
+    sig { params(tap: Tap).returns(T::Array[Formula]) }
+    def self.installed_formulae_for(tap:)
+      tap.formula_names.filter_map do |formula_name|
+        next unless installed_formulae_names.include?(T.must(formula_name.split("/").last))
+
+        formula = begin
+          Formulary.factory(formula_name)
+        rescue
+          # Don't blow up because of a single unavailable formula.
+          next
+        end
+
+        # Can't use Formula#any_version_installed? because it doesn't consider
+        # taps correctly.
+        formula if formula.installed_kegs.any? { |keg| keg.tab.tap == tap }
+      end
+    end
+
+    sig { returns(T::Set[String]) }
+    def self.installed_formulae_names
+      @installed_formulae_names ||= Formula.installed_formula_names.to_set.freeze
+    end
+    private_class_method :installed_formulae_names
+
+    # All installed casks currently available in a tap by cask full name.
+    sig { params(tap: Tap).returns(T::Array[Cask::Cask]) }
+    def self.installed_casks_for(tap:)
+      tap.cask_tokens.filter_map do |cask_token|
+        next unless installed_cask_tokens.include?(T.must(cask_token.split("/").last))
+
+        cask = begin
+          Cask::CaskLoader.load(cask_token)
+        rescue
+          # Don't blow up because of a single unavailable cask.
+          next
+        end
+
+        cask if cask.installed?
+      end
+    end
+
+    sig { returns(T::Set[String]) }
+    def self.installed_cask_tokens
+      @installed_cask_tokens ||= Cask::Caskroom.tokens.to_set.freeze
+    end
+    private_class_method :installed_cask_tokens
+  end
+end