# Codesigning macOS apps with GNUstep-make
GNUstep-make adds a stamp file (for example, `stamp.make`) inside the .app bundle directory, for internal dependency tracking. The macOS `codesign` tool rejects bundles containing unexpected files, so the stamp file must be removed before you sign your app.

Use a [GNUstep-make hook](gnustep-make-hooks) to remove the stamp file before signing, for example, in a `before-install::` hook.