diff --git a/Library/Homebrew/cask/artifact/moved.rb b/Library/Homebrew/cask/artifact/moved.rb
index 48861a0f61..e12d0160f7 100644
--- a/Library/Homebrew/cask/artifact/moved.rb
+++ b/Library/Homebrew/cask/artifact/moved.rb
@@ -92,9 +92,9 @@ module Cask
 
         if target.directory?
           if target.writable?
-            source.children.each { |child| FileUtils.move(child, target + child.basename) }
+            source.children.each { |child| FileUtils.move(child, target/child.basename) }
           else
-            command.run!("/bin/cp", args: ["-pR", "#{source}/*", "#{source}/.*", "#{target}/"],
+            command.run!("/bin/cp", args: ["-pR", *source.children, target],
                                     sudo: true)
           end
           Quarantine.copy_xattrs(source, target)
diff --git a/Library/Homebrew/test/cask/artifact/app_spec.rb b/Library/Homebrew/test/cask/artifact/app_spec.rb
index 796f03f19f..f3ba605472 100644
--- a/Library/Homebrew/test/cask/artifact/app_spec.rb
+++ b/Library/Homebrew/test/cask/artifact/app_spec.rb
@@ -2,7 +2,7 @@
 
 describe Cask::Artifact::App, :cask do
   let(:cask) { Cask::CaskLoader.load(cask_path("local-caffeine")) }
-  let(:command) { SystemCommand }
+  let(:command) { NeverSudoSystemCommand }
   let(:adopt) { false }
   let(:force) { false }
   let(:app) { cask.artifacts.find { |a| a.is_a?(described_class) } }
@@ -334,5 +334,29 @@ describe Cask::Artifact::App, :cask do
 
       expect(contents_path).to exist
     end
+
+    it "properly handles non-writable directories" do
+      install_phase
+
+      source_contents_path = source_path.join("Contents")
+      target_contents_path = target_path.join("Contents")
+
+      allow(app.target).to receive(:writable?).and_return false
+      allow(command).to receive(:run!).with(any_args).and_call_original
+
+      expect(command).to receive(:run!)
+        .with("/bin/cp", args: ["-pR", source_contents_path, target_path],
+                         sudo: true)
+        .and_call_original
+      expect(FileUtils).not_to receive(:move).with(source_contents_path, an_instance_of(Pathname))
+
+      app.uninstall_phase(command: command, force: force, successor: cask)
+      expect(target_contents_path).not_to exist
+      expect(target_path).to exist
+      expect(source_contents_path).to exist
+
+      app.install_phase(command: command, adopt: adopt, force: force, predecessor: cask)
+      expect(target_contents_path).to exist
+    end
   end
 end