diff --git a/Library/Homebrew/cask/lib/hbc/system_command.rb b/Library/Homebrew/cask/lib/hbc/system_command.rb
index c21e87d8e8..48d57689ca 100644
--- a/Library/Homebrew/cask/lib/hbc/system_command.rb
+++ b/Library/Homebrew/cask/lib/hbc/system_command.rb
@@ -47,7 +47,7 @@ module Hbc
       @must_succeed = must_succeed
       options.extend(HashValidator).assert_valid_keys(:chdir)
       @options = options
-      @env = { "PATH" => ENV["PATH"] }.merge(env)
+      @env = env
 
       @env.keys.grep_v(/^[\w&&\D]\w*$/) do |name|
         raise ArgumentError, "Invalid variable name: '#{name}'"
@@ -55,7 +55,7 @@ module Hbc
     end
 
     def command
-      [*sudo_prefix, executable, *args]
+      [*sudo_prefix, *env_args, executable, *args]
     end
 
     private
@@ -64,18 +64,22 @@ module Hbc
 
     attr_predicate :sudo?, :print_stdout?, :print_stderr?, :must_succeed?
 
+    def env_args
+      return [] if env.empty?
+
+      variables = env.map do |name, value|
+        sanitized_name = Shellwords.escape(name)
+        sanitized_value = Shellwords.escape(value)
+        "#{sanitized_name}=#{sanitized_value}"
+      end
+
+      ["env", *variables]
+    end
+
     def sudo_prefix
       return [] unless sudo?
       askpass_flags = ENV.key?("SUDO_ASKPASS") ? ["-A"] : []
-      prefix = ["/usr/bin/sudo", *askpass_flags, "-E"]
-
-      env.each do |name, value|
-        sanitized_name = Shellwords.escape(name)
-        sanitized_value = Shellwords.escape(value)
-        prefix << "#{sanitized_name}=#{sanitized_value}"
-      end
-
-      prefix << "--"
+      ["/usr/bin/sudo", *askpass_flags, "-E", "--"]
     end
 
     def assert_success
@@ -97,11 +101,7 @@ module Hbc
       executable, *args = expanded_command
 
       raw_stdin, raw_stdout, raw_stderr, raw_wait_thr =
-        # We need to specifically use `with_env` for `PATH`, otherwise
-        # Ruby itself will not look for the executable in `PATH`.
-        with_env "PATH" => env["PATH"] do
-          Open3.popen3(env, [executable, executable], *args, **options)
-        end
+        Open3.popen3([executable, executable], *args, **options)
 
       write_input_to(raw_stdin)
       raw_stdin.close_write
diff --git a/Library/Homebrew/test/cask/system_command_spec.rb b/Library/Homebrew/test/cask/system_command_spec.rb
index 1c139a167f..f08193e652 100644
--- a/Library/Homebrew/test/cask/system_command_spec.rb
+++ b/Library/Homebrew/test/cask/system_command_spec.rb
@@ -15,10 +15,10 @@ describe Hbc::SystemCommand, :cask do
       its("run!.stdout") { is_expected.to eq("123") }
 
       describe "the resulting command line" do
-        it "does not include the given variables" do
+        it "includes the given variables explicitly" do
           expect(Open3)
             .to receive(:popen3)
-            .with(a_hash_including("PATH"), ["env"] * 2, *env_args, {})
+            .with(["env", "env"], "A=1", "B=2", "C=3", "env", *env_args, {})
             .and_call_original
 
           subject.run!
@@ -41,9 +41,8 @@ describe Hbc::SystemCommand, :cask do
         it "includes the given variables explicitly" do
           expect(Open3)
             .to receive(:popen3)
-            .with(an_instance_of(Hash), ["/usr/bin/sudo"] * 2,
-                "-E", a_string_starting_with("PATH="),
-                "A=1", "B=2", "C=3", "--", "env", *env_args, {})
+            .with(["/usr/bin/sudo", "/usr/bin/sudo"], "-E", "--",
+                  "env", "A=1", "B=2", "C=3", "env", *env_args, {})
             .and_wrap_original do |original_popen3, *_, &block|
               original_popen3.call("/usr/bin/true", &block)
             end
@@ -197,7 +196,7 @@ describe Hbc::SystemCommand, :cask do
     end
   end
 
-  it "looks for executables in custom PATH" do
+  it "looks for executables in a custom PATH" do
     mktmpdir do |path|
       (path/"tool").write <<~SH
         #!/bin/sh
diff --git a/Library/Homebrew/test/support/helper/cask/fake_system_command.rb b/Library/Homebrew/test/support/helper/cask/fake_system_command.rb
index 211b081888..93e1c194f1 100644
--- a/Library/Homebrew/test/support/helper/cask/fake_system_command.rb
+++ b/Library/Homebrew/test/support/helper/cask/fake_system_command.rb
@@ -1,5 +1,5 @@
 def sudo(*args)
-  ["/usr/bin/sudo", "-E", "PATH=#{ENV["PATH"]}", "--"] + args.flatten
+  ["/usr/bin/sudo", "-E", "--"] + args.flatten
 end
 
 module Hbc
diff --git a/Library/Homebrew/test/support/helper/spec/shared_examples/hbc_staged.rb b/Library/Homebrew/test/support/helper/spec/shared_examples/hbc_staged.rb
index 1e29456f31..b69c116fdb 100644
--- a/Library/Homebrew/test/support/helper/spec/shared_examples/hbc_staged.rb
+++ b/Library/Homebrew/test/support/helper/spec/shared_examples/hbc_staged.rb
@@ -80,7 +80,7 @@ shared_examples Hbc::Staged do
     allow(staged).to receive(:Pathname).and_return(fake_pathname)
 
     Hbc::FakeSystemCommand.expects_command(
-      ["/usr/bin/sudo", "-E", "PATH=#{ENV["PATH"]}", "--", "/usr/sbin/chown", "-R", "--", "fake_user:staff", fake_pathname],
+      sudo("/usr/sbin/chown", "-R", "--", "fake_user:staff", fake_pathname),
     )
 
     staged.set_ownership(fake_pathname.to_s)
@@ -93,7 +93,7 @@ shared_examples Hbc::Staged do
     allow(staged).to receive(:Pathname).and_return(fake_pathname)
 
     Hbc::FakeSystemCommand.expects_command(
-      ["/usr/bin/sudo", "-E", "PATH=#{ENV["PATH"]}", "--", "/usr/sbin/chown", "-R", "--", "fake_user:staff", fake_pathname, fake_pathname],
+      sudo("/usr/sbin/chown", "-R", "--", "fake_user:staff", fake_pathname, fake_pathname),
     )
 
     staged.set_ownership([fake_pathname.to_s, fake_pathname.to_s])
@@ -105,7 +105,7 @@ shared_examples Hbc::Staged do
     allow(staged).to receive(:Pathname).and_return(fake_pathname)
 
     Hbc::FakeSystemCommand.expects_command(
-      ["/usr/bin/sudo", "-E", "PATH=#{ENV["PATH"]}", "--", "/usr/sbin/chown", "-R", "--", "other_user:other_group", fake_pathname],
+      sudo("/usr/sbin/chown", "-R", "--", "other_user:other_group", fake_pathname),
     )
 
     staged.set_ownership(fake_pathname.to_s, user: "other_user", group: "other_group")