diff --git a/collects/setup/option-sig.ss b/collects/setup/option-sig.ss
index c9b2d0a9f7..ed83caa00b 100644
--- a/collects/setup/option-sig.ss
+++ b/collects/setup/option-sig.ss
@@ -17,4 +17,5 @@
      force-unpacks
      specific-collections
      archives
-     current-target-directory-getter)))
+     current-target-directory-getter
+     current-target-plt-directory-getter)))