diff --git a/updater/updater.c b/updater/updater.c
index aa626d2..6bc4f40 100644
--- a/updater/updater.c
+++ b/updater/updater.c
@@ -63,6 +63,7 @@
     // Extract the script from the package.
 
     char* package_data = argv[3];
+    setenv("UPDATE_PACKAGE", package_data, 1);
     ZipArchive za;
     int err;
     err = mzOpenZipArchive(package_data, &za);