diff --git a/Library/Homebrew/bundle/commands/exec.rb b/Library/Homebrew/bundle/commands/exec.rb
index 9f73eadc01..b9251cd2a6 100644
--- a/Library/Homebrew/bundle/commands/exec.rb
+++ b/Library/Homebrew/bundle/commands/exec.rb
@@ -11,47 +11,9 @@ module Homebrew
   module Bundle
     module Commands
       module Exec
-        # Homebrew's global environment variables that we don't want to leak into
-        # the `brew bundle exec` environment.
-        HOMEBREW_ENV_CLEANUP = %w[
-          HOMEBREW_HELP_MESSAGE
-          HOMEBREW_API_DEFAULT_DOMAIN
-          HOMEBREW_BOTTLE_DEFAULT_DOMAIN
-          HOMEBREW_BREW_DEFAULT_GIT_REMOTE
-          HOMEBREW_CORE_DEFAULT_GIT_REMOTE
-          HOMEBREW_DEFAULT_CACHE
-          HOMEBREW_DEFAULT_LOGS
-          HOMEBREW_DEFAULT_TEMP
-          HOMEBREW_REQUIRED_RUBY_VERSION
-          HOMEBREW_PRODUCT
-          HOMEBREW_SYSTEM
-          HOMEBREW_PROCESSOR
-          HOMEBREW_PHYSICAL_PROCESSOR
-          HOMEBREW_BREWED_CURL_PATH
-          HOMEBREW_USER_AGENT_CURL
-          HOMEBREW_USER_AGENT
-          HOMEBREW_GENERIC_DEFAULT_PREFIX
-          HOMEBREW_GENERIC_DEFAULT_REPOSITORY
-          HOMEBREW_DEFAULT_PREFIX
-          HOMEBREW_DEFAULT_REPOSITORY
-          HOMEBREW_AUTO_UPDATE_COMMAND
-          HOMEBREW_BREW_GIT_REMOTE
-          HOMEBREW_COMMAND_DEPTH
-          HOMEBREW_CORE_GIT_REMOTE
-          HOMEBREW_MACOS_VERSION_NUMERIC
-          HOMEBREW_MINIMUM_GIT_VERSION
-          HOMEBREW_MACOS_NEWEST_UNSUPPORTED
-          HOMEBREW_MACOS_OLDEST_SUPPORTED
-          HOMEBREW_MACOS_OLDEST_ALLOWED
-          HOMEBREW_GITHUB_PACKAGES_AUTH
-        ].freeze
-
         PATH_LIKE_ENV_REGEX = /.+#{File::PATH_SEPARATOR}/
 
         def self.run(*args, global: false, file: nil, subcommand: "", services: false)
-          # Cleanup Homebrew's global environment
-          HOMEBREW_ENV_CLEANUP.each { |key| ENV.delete(key) }
-
           # Store the old environment so we can check if things were already set
           # before we start mutating it.
           old_env = ENV.to_h
@@ -149,15 +111,36 @@ module Homebrew
           # For commands which aren't either absolute or relative
           raise "command was not found in your PATH: #{command}" if command.exclude?("/") && which(command).nil?
 
+          # Don't need to export Homebrew internal variables that won't be used by other tools.
+          # Those Homebrew needs have already been set to global constants and/or are exported again later.
+          # Setting these globally can interfere with nested Homebrew invocations/environments.
+          ENV.delete_if { |key, _| key.start_with?("HOMEBREW_", "PORTABLE_RUBY_") }
+
           if subcommand == "env"
             ENV.sort.each do |key, value|
               # No need to export empty values.
               next if value.blank?
 
-              # Skip exporting non-Homebrew things that were already set in the old environment.
-              next if !key.start_with?("HOMEBREW_") && old_env.key?(key) && old_env[key] == value
+              # Skip exporting things that were the same in the old environment.
+              old_value = old_env[key]
+              next if old_value == value
 
-              puts "export #{key}=\"#{Utils::Shell.sh_quote(value)}\""
+              # Look for PATH-like environment variables
+              if key.include?("PATH") && value.match?(PATH_LIKE_ENV_REGEX)
+                old_values = old_value.to_s.split(File::PATH_SEPARATOR)
+                path = PATH.new(value)
+                           .reject do |path_value|
+                  # Exclude Homebrew shims from the PATH as they don't work
+                  # without all Homebrew environment variables.
+                  # Exclude existing/old values as they've already been exported.
+                  path_value.include?("/Homebrew/shims/") || old_values.include?(path_value)
+                end
+                next if path.blank?
+
+                puts "export #{key}=\"#{Utils::Shell.sh_quote(path.to_s)}:${#{key}:-}\""
+              else
+                puts "export #{key}=\"#{Utils::Shell.sh_quote(value)}\""
+              end
             end
             return
           end
diff --git a/Library/Homebrew/test/bundle/commands/exec_spec.rb b/Library/Homebrew/test/bundle/commands/exec_spec.rb
index a6cc0114de..101ab72f05 100644
--- a/Library/Homebrew/test/bundle/commands/exec_spec.rb
+++ b/Library/Homebrew/test/bundle/commands/exec_spec.rb
@@ -65,12 +65,10 @@ RSpec.describe Homebrew::Bundle::Commands::Exec do
 
     context "with env command" do
       it "outputs the environment variables" do
-        ENV["HOMEBREW_PREFIX"] = "/opt/homebrew"
-        ENV["HOMEBREW_PATH"] = "/usr/bin"
         allow(OS).to receive(:linux?).and_return(true)
 
         expect { described_class.run("env", subcommand: "env") }.to \
-          output(/HOMEBREW_PREFIX="#{ENV.fetch("HOMEBREW_PREFIX")}"/).to_stdout
+          output(/export PATH=".+:\${PATH:-}"/).to_stdout
       end
     end