diff --git a/data/build-package.common b/data/build-package.common
index ef01f14..b67b7e5 100644
--- a/data/build-package.common
+++ b/data/build-package.common
@@ -237,6 +237,8 @@ error () {
 
 sum_sign_package () {
 	cd "${CWD}"
-	sha256sum "${ZIP}" > "${ZIP}.sha256"
+	cd "$(dirname "${ZIP}")"
+	sha256sum "$(filename "${ZIP}")" > "${ZIP}.sha256"
+	cd "${CWD}"
 	gpg --sign --detach-sign "${ZIP}.sha256"
 }