diff --git a/Library/Homebrew/test/cmd/install_spec.rb b/Library/Homebrew/test/cmd/install_spec.rb
index 3840f00f1e..dbf9d6a358 100644
--- a/Library/Homebrew/test/cmd/install_spec.rb
+++ b/Library/Homebrew/test/cmd/install_spec.rb
@@ -82,5 +82,6 @@ describe "brew install" do
       .and be_a_success
     expect(HOMEBREW_CELLAR/"testball1/0.1/bin/test").to be_a_file
     expect(HOMEBREW_CELLAR/"testball1/0.1/bin/test.dSYM").to be_a_directory if OS.mac?
+    expect(HOMEBREW_CACHE/"Sources/testball1").to be_a_directory
   end
 end